Doctor Who Target Books is a 20-book series with 19 released primary works first released in 1975 with contributions by Terrance Dicks, Malcolm Hulke, Ian Marter, Gareth Roberts, Eric Pringle, Eric Saward, Wally K. Daly, Stephen Wyatt, Ben Aaronovitch, Gary Russell, Russell T. Davies, Robert Shearman, Jenny T. Colgan, Keith Temple, Phil Ford, Mark Gatiss, and Pete McTighe.