Please note that some of the pseudonyms listed are Publishing house names, which may have been used by dozens of writers so Reasearch is the big thing.

I don't vouch for the following, As i've compiled this from the net & posting it here as it may be of some use.

Happy reading!

Zak.

Asimov, Isaac (1920-1992)
[Dr. A, George E. Dale, The Good Doctor, Paul French, H.B. Ogden]

Bradley, Marion Zimmer (1930-)
[Lee Chapman, John Dexter, Miriam Gardner, Valerie Graves, Morgan Ives, Brian Morley, Dee O'Brien, John Jay Wells]

Bradbury, Ray(mond Douglas) (1920-)
[Guy Amory, D.R. Banat, Edward Banks, Anthony Corvais, Cecil Clairbourne Cunningham, E. Cunningham, Leonard Douglas, Brian Eldred, William Elliott, Hollerbochen, Omega, Ron Reynolds, Doug Rogers, Douglas Spaulding, Leonard Spaulding, Brett Sterling, D. Lerium Tremaine]

Burroughs, Edgar Rice (1875-1950)
[Norman (Normal?) Bean, Craig Shaw Gardner, John Tyler McCulloch, John Tyler McCullough]

Card, Orson Scott (1951-)
[Dinah Kirkham, Noam D. Pellume, Bryon Walley]

Catto, Max
[Simon Kent]

Christie, Agatha (Mary Clarissa Miller) (1890-1976)
[Agatha Christie Mallowan, Mary Westmacott]

Creasey, John (1908-1973)
[Gordon Ashe, M.E. Cooke, Margaret Cooke, Henry St. John Cooper, Credo, Norman Deane, Elise Fecamps, Robert Caine Frazer, Patrick Gill, Michael Halliday, Charles Hogarth, Brian Hope, Colin Hughes, Kyle Hunt, Abel Mann, Peter Manton, J.J. Marric, James Marsden, Richard Martin, Rodney Matheson, Anthony Morton, Ken Ranger, William K. Reilly, Tex Riley, Henry St. John, Jimmy Wilde, Jeremy York]

de Camp, L(yon) Sprague (1907)
[Lymon R. Lyon, J. Wellington Wells]

Denning, Troy (1958-)
[Richard Awlinson]

de Lint, Charles (Henri Diederick Hoefsmit) (1951-)
[Samuel M. Key, Wendelessen]

Edson, J(ohn) T(homas) (1928-)
[Rod Denver, Chuck Nolan]

Evanovich, Janet
[Stephie (Steffie) Hall]

Farmer, Philip José (1918-)
[Cordwainer Bird, Paul Chapin, Maxwell Grant, Dane Helstrom, Rod Keen, Harry 'Bunny' Manders, William Norfolk, Kenneth Robeson, Jonathan Swift Somers III, Leo Queequeg Tincrowd(o/e)r, Kilgore Trout, John H. Watson MD]

Fawcett, Bill (William Brian) (1947-)
[Quinn Fawcett]

Feder, Robert Arthur (1909-1969)
[Robert Arthur, Alfred Hitchcock]

Follett, Ken(neth Martin) (1949-)
[Martin Martinsen, Simon Myles, Zachary Stone]

Francis, Richard Stanley (1920-)
[Dick Francis]

Geisel, Theodor Seuss (1904-1991)
[Ted Geisel, Theo Le Sieg, Dr. Seuss]

Gibson, Walter B(rown) (1897-1985)
[Andy Adams, Ishi Black, Douglas Brown, Maxwell Grant, Harry Hershfield, Harry Houdini, Maborushi Kineji]

Graseman, Barbara (1930-)
[Ruth Rendell, Barbara Vine]

Hagberg, David J.
[Sean Flannery, David James, Robert Pell, Eric Ramsey]

Heinlein, Robert Anson (1907-1988)
[Anson MacDonald, Lyle Monroe, John Riverside, Caleb Saunders, Elma Wentz, Simon York]

Hoskin, Cyril Henry
[T. Lopsang Rampa]

Hutson, Shaun (1958-)
[Nick Black, Robert Neville, Frank Taylor]

James, Laurence (1942-)
[James Axler, James Darke, Arthur Frazier, Charles C. Garrett, William M. James, Neil Langholm, Jonathan May, John J. McLaglen, James McPhee, Klaus Netzen, Phil Nolan, Mick Norman]

Jacob, Piers Anthony Dillingham (1934-)
[Piers Anthony, Pier Xanthony]

King, Stephen (Edwin) (1947-)
[Richard Bachman, John Swithen]

Krentz, Jayne Ann (1948-)
[Jayne Bentley, Jayne Castle, Amanda Class, Amanda Glass, Stephanie James, Amanda Quick, Jayne Taylor]

Koontz, Dean (Ray) (1945-)
[David Axton, Leonard Chris, Brian Coffey, Deanna Dwyer, K.R. Dwyer, John Hill, Leigh Nichols, Anthony North, Richard Paige, Owen West, Aaron Wolfe]

LaMoore, Louis Dearborn (1908-1988)
[Tex Burns, Louis L'Amour, Jim Mayo]

Laymon, Richard (Carl) (1947-)
[Richard Kelly]

Lewis, C(live) S(taples) (1898-1963)
[N.W. Clerk, Clive Hamilton, Jack Lewis, N.W.]

Lofts, Nora (1904-)
[Juliet Astley, Peter Curtis]

Lombino, Salvatore A. (1926-)
[John Abbott, Curt Cannon, Hunt Collins, Ezra Hannon, Evan Hunter, Richard Marsten, Ed McBain, Craig Rice]

Ludlum, Robert (1927-)
[Brian House, Jonathon Ryder, Michael Shepherd]

Mann, Vivian Stuart
[Barbara Allen, William Stuart Long, Alex Stuart, Robyn Stuart]

Mear(e)s, Leonard F.
[Marshall Grover, Marshall McCoy, Johnny Nelson]

Moorcock, Michael (John) (1939-)
[Bill Barclay, William Ewert Barclay, Michael Barrington, E(dward) P. Bradbury, James Colvin, Philip James, Hank Janson, Desmond Reid]

Offutt, Andrew J(efferson V.) (1934-)
[John Cleve, Jeff Douglas, Farrah Fawkes, Baxter Giles, John X. Williams, Turk Winter]

Ogden, Margaret Astrid Lindholm (1952-)
[Robin Hobb, Megan Lindholm]

Pohl, Frederik (George), (Jr.) (1919-)
[Elton V. Andrews, Henry De Costa, Paul Flehr, S.D. Gottesman, Warren F. Howard, Walt Lasly, Paul Dennis Lavond, James MacCreigh, Scott Mariner, Ernest Mason, Ernst Mason, Edson McCann, Jordan Park, Charles Satterfield, Dirk Wylie, Allen Zweig]

Rasmussen, Alis A. (1958-)
[Kate Elliott, Alysse Lemery]

Raymond, René Brabazon (1906-1985)
[James Hadley Chase, James L. Docherty, Ambrose Grant, Raymond Marshall]

Reback, Janet Taylor Caldwell (1900-1985)
[Janet Miriam Taylor Holland Caldwell, Taylor Caldwell, Taylor Caldwell Prestie, Max Reiner]

Reichert, Miriam Susan Zucker (1962-)
[Mickey Zucker Reichert, Miriam S. Zucker]

Rice, Howard Allan Frances O'Brien (1941-)
[Anne Rampling, Anne Rice, A.N. Roquelaure]

Rigney, James (Oliver), Jr. (1948-)
[Robert Jordan, Chang Lung, Reagan O'Neal, Jackson O'Reilly]

Roberts, Nora (1950-)
[Sarah Hardesty, J.D. Robb, Nora Roberts Smith, Eleanor Wilder]

Silverberg, Robert (1935-)
[Gordon Aghill, Robert Arnette, T.D. Bethlen, Alexander Blade, Ralph Burke, Robert Burke, Walter Chapman, Dirk Clinton, Walter Drummond, Don Elliot(t), Richard Greer, E.K. Jarvis, Ivar Jorgenson, Warren Kastel, Calvin M. Knox, Dan Malcom, Webber Martin, Ray McKenzie, Alex Merriman, Clyde Mitchell, David Osborne, George Osborne, Robert Randall, Ellis Robertson, Eric Rodman, Lee Sebastian, Leonard G. Spencer, S.M. Tenneshaw, Hall Thornton, Gerald Vance, Richard F. Watson, L.T. Woodward MD]

Tepper, Sheri S. (1929-)
[E.E. Horlak, B.J. Oliphant, A.J. Orde]

Tubb, E(dwin) C(harles) (1919-)
[Chuck Adams, Jud Cary, J.F. Clarkson, Norman Dale, Robert D. Ennissh, James S. Farrow, James R. Fenner, R.H. Godfrey, Charles S. Graham, Charles Gray, Charles Grey, Volsted Gridban, Alan Guthrie, George Holt, Gill Hunt, Alan Innes, E.F. Jackson, Gordon Kent, Gregory Kern, Duncan Lamont, King Lang, Mike Lantry, P. Lawrence, Chet Lawson, Arthur MacLean, Carl Maddox, Phillip Martyn, John Mason, Carl Moulton, Gavin Neal, L.C. Powers, M.L. Powers, Louis Preston, Edward Richards, Paul Schofield, John Seabright, Brian (Bryan) Shaw, Roy Sheldon, John Stevens, Edward Thomson, Ken Wainwright, Frank Weight, Douglas West, Eric Wilding, Frank Winnard]

Turtledove, Harry (1949-)
[Eric G. Iverson]

Vardeman, Robert (Bob) E(dward) (1947-)
[Victor W. Appleton II, Paul Kenyon, Daniel Moran]

Ward, Arthur (Henry) Sarsfield (1883-1959)
[Michael Furey, Sax Rohmer]

Watkins, Diana Jean Gabaldon (1952-)
[Diana Gabaldon]

Weiss, Erich (1874-1926)
[Harry Houdini]

Westlake, D(onald) E(dwin) (1933-)
[John B. Allan, Curt Clark, Tucker Coe, Timothy J. Culver, J. Morgan Cunningham, Samuel Holt, Sheldon Lord, Richard Stark]

Whittington, Harry (1915-)
[Ashley Carter, Robert Hart Davis, Tabor Evans, Whit Harrison, Kel Holland, Harriet Kathryn Myers, Blaine Stevens, Clay Stuart, Hondo Wells, Harry White, Hallam Whitney]

Yates, Alan Geoffrey (1923-)
[Carter Brown, Peter Carter Brown, Peter Carter-Brown, Caroline Farr, A.G. Yates]

Yermakov, Nicholas V(alentin) (1951)
[Simon Hawke, J.D. Masters, J.D. Masters]

Zelazny, Roger (Joseph) (1937-1995)
[Harrison Denmark]