The Infocom Gallery: Ballyhoo - High quality scans of box, circus program, ticket, balloon, and trade card. - http://infocom.elsewhere.org/gallery/ballyhoo/ballyhoo.html
Infocom Documentation Project - PDF file of scanned originial game manual. - http://infodoc.plover.net/manuals/temp/ballyhoo.pdf
Review by Matthew Murray - Capsule review. "An interesting game, but certainly not one of Infocom's more intense or defined." - http://www.matthewmurray.net/Reviews/ComputerGames/Ballyhoo.html