The Secret Seven

 The Secret Seven  was a series of mystery books written by Enid Blyton. According to the Tenth Doctor, The Troubleseekers series was a rip-off of this and The Famous Five. (PROSE: The Mystery of the Haunted Cottage)

Templeton sneered that Allison Williams was not one of the Seven and that Ian Gilmore was not Timmy the "lapdog". Gilmore deadpanned that he was confusing it with The Famous Five. (AUDIO: Changing of the Guard)