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Schuppin GT, Bonner-Weir S, Montana E, Kaiser N, Weir GC.Schuppin GT, et al.In Vitro Cell Dev Biol Anim. 1993 Apr;29A(4):339-44. doi: 10.1007/BF02633963.In Vitro Cell Dev Biol Anim. 1993.PMID: 8320184