IMBERT, FM, RICHARDS, JH. (1993). PROTANDRY, INCOMPATIBILITY, AND SECONDARY POLLEN PRESENTATION IN CEPHALANTHUS-OCCIDENTALIS (RUBIACEAE)
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AMERICAN JOURNAL OF BOTANY, 80(4), 395-404. 10.2307/2445386
IMBERT, FM, RICHARDS, JH. (1993). PROTANDRY, INCOMPATIBILITY, AND SECONDARY POLLEN PRESENTATION IN CEPHALANTHUS-OCCIDENTALIS (RUBIACEAE)
. AMERICAN JOURNAL OF BOTANY, 80(4), 395-404. 10.2307/2445386