Twin-Fin Surfing, 1970Credits: Hal Jepsen, John SeversonEncyclopedia of SurfingCarroll, CorkyRiddle, Jtwin-finHistory of SurfingTwo Fins, More WinsInterviewsCorky Carroll (1996)J RiddleFeaturesMARK RICHARDS: "NOT PRETTY, BUT PLENTY RADICAL"TWIN-FINS: YOU SPIN ME RIGHT ROUNDThe Sunday JointSUNDAY JOINT, 8-12-2018: MARK RICHARDS AND THE TWIN-FINVideosCorky Carroll, 1970 Twin-Fin Session, Cottons PointFaster Twin-Fin! Kill! Kill!Mark RichardsTwin-Fin Surfing, Early '80s