Flyer promoting a "spring mating service" of fellow Yippies held on March 22, [1968] in Grand Central Station. "It's a spring mating service celebrating the equinox, a back-scratching party, a roller-skating rink, a theatre... With you, performer and audience. Get acquainted with other yippies now, for other yiptivities, and Chicago Y.I.P. festival this summer."