Paul Farquhar
Legend
Given there is a fair bit of misinformation floating around I've put in some info about the names on the list. The dates are when their writings where published (according to Wikipedia), not when they lived.
Name Dates Known for
Anderson, Poul (1948–2001) Three Hearts and Three Lions
Bellairs, John (1966–1991) The Face in the Frost, The House with a Clock in Its Walls
Brackett, Leigh (1940-1980) The Empire Strikes Back(?)
Brown, Frederic (1938-1965) Star Trek TOS (Arena)
Burroughs, Edgar Rice (1911-1950) Tarzan, John Carter
Carter, Lin (1965-1998) copying other authors on this list
de Camp, L. Sprague (1937–1996) ditto
de Camp & Pratt (both of these are listed separately)
Derleth, August (1937-1973) another plagiarist
Dunsany, Lord (1905-1957) The King of Elfland's Daughter, inventing the genre
Farmer, P. J. (1952-2009) Riverworld
Fox, Gardner (1939-1973) The Flash, Batman
Howard, R. E. (1926-1936) Conan
Lanier, Sterling (1961-1983) The Peculiar Exploits of Brigadier Ffellowes
Leiber, Fritz (1958-1988) Lankhmar
Lovecraft, H. P. (1917-1937) The Call of Cthulhu
Merritt, A. (1917–1943) The Devil-Doll (film, adapted from Burn, Witch, Burn!)
Moorcock, Michael (1957-date) Elric
Norton, Andre (1934-2005) Quag Keep
Offutt, Andrew J. (1970-2004) Thieves' World, Erotica
Pratt, Fletcher (1940-1956) Being ghost-written by L. Sprague de Camp
Saberhagen, Fred (1964-2005) Book of Swords
St. Clair, Margaret (1956-1974) The Best of Margaret St. Clair
Tolkien, J. R. R. (1937-1967) Translating Sir Gawain and the Green Knight
Vance, Jack (1950-2009) The Dying Earth
Weinbaum, Stanley (1933-1935) A Martian Odyssey, dying before he could write anything else
Wellman, Manley Wade (1929-1986) Nothing I've heard of
Williamson, Jack (1926-2006) Legion of Space
Zelazny, Roger (1970-1995) The Chronicles of Amber
Name Dates Known for
Anderson, Poul (1948–2001) Three Hearts and Three Lions
Bellairs, John (1966–1991) The Face in the Frost, The House with a Clock in Its Walls
Brackett, Leigh (1940-1980) The Empire Strikes Back(?)
Brown, Frederic (1938-1965) Star Trek TOS (Arena)
Burroughs, Edgar Rice (1911-1950) Tarzan, John Carter
Carter, Lin (1965-1998) copying other authors on this list
de Camp, L. Sprague (1937–1996) ditto
de Camp & Pratt (both of these are listed separately)
Derleth, August (1937-1973) another plagiarist
Dunsany, Lord (1905-1957) The King of Elfland's Daughter, inventing the genre
Farmer, P. J. (1952-2009) Riverworld
Fox, Gardner (1939-1973) The Flash, Batman
Howard, R. E. (1926-1936) Conan
Lanier, Sterling (1961-1983) The Peculiar Exploits of Brigadier Ffellowes
Leiber, Fritz (1958-1988) Lankhmar
Lovecraft, H. P. (1917-1937) The Call of Cthulhu
Merritt, A. (1917–1943) The Devil-Doll (film, adapted from Burn, Witch, Burn!)
Moorcock, Michael (1957-date) Elric
Norton, Andre (1934-2005) Quag Keep
Offutt, Andrew J. (1970-2004) Thieves' World, Erotica
Pratt, Fletcher (1940-1956) Being ghost-written by L. Sprague de Camp
Saberhagen, Fred (1964-2005) Book of Swords
St. Clair, Margaret (1956-1974) The Best of Margaret St. Clair
Tolkien, J. R. R. (1937-1967) Translating Sir Gawain and the Green Knight
Vance, Jack (1950-2009) The Dying Earth
Weinbaum, Stanley (1933-1935) A Martian Odyssey, dying before he could write anything else
Wellman, Manley Wade (1929-1986) Nothing I've heard of
Williamson, Jack (1926-2006) Legion of Space
Zelazny, Roger (1970-1995) The Chronicles of Amber