Retrieved 25 January 2015. ↑ "Bellybutton Fetish: Erotic and naughty stories for bellybutton lovers[Book]". appannie.com. Retrieved 25 January 2015. ↑ "Bellybutton Fetish: Erotic and naughty stories for bellybutton lovers". goodreads.com. Retrieved 25 January 2015. ↑ "Navel Maneuvers 2: Bellybutton-Tickling Erotica". mtjpub.com.