Deletion of The Firesign Theatre's Big Mystery Joke Book

Comment: to The_Firesign_Theatre#Bibliography. The only reference I could find online was a brief mention inhttp://www.broadwayworld.com/los-angeles/article/Nick-Danger-Celebrates-40th-Birthday-with-Firesign-Theatres-FORWARD-INTO-THE-PAST-20090917#. Since it was published in 1974, there are likely to be offline references, but until this is confirmed, this book doesn't pass 
Stance: merge
Cited policy: Wikipedia:Notability (WP:NBOOK)