101 Things To Do With A TARDIS
From Tardis Wiki, the free Doctor Who reference
101 Things To Do With A TARDIS was a "popular best-seller".
Its 96th entry suggested using two identically-shaped TARDISes as bookends for "Target Books' never-ending collection of Who books". The Seventh Doctor eventually used this tip. (NOTVALID: Excerpts From the Best-Seller; '101 Things To Do With A TARDIS'.)