Doctor Who: Target Books is a 23-book series with 23 released primary works first released in 1964 with contributions by David Whitaker, Ian Marter, Bill Strutton, William Emms, Paul Erickson, Eric Schlosser, Donald Cotton, Terrance Dicks, Malcolm Hulke, Philip Hinchcliffe, Philip Hinschcliffe, Gareth Roberts, Stephen Wyatt, and Paul Cornell.