. . "Happening '68" . "1968-01-06" . "It's Happening!" . "76" . . . "Happening '68" . "Happening '69" . . . . . . "1500.0" . . "Happening '69 (January 4-25) & Happening from February 1 to September 20, 1969)" . "Happening" . . . . "2" . . . "1969-09-20" .