[1]
L. Goldberg, “Patterns of nectar production and composition, and morphology of floral nectaries in <i>Helicteres guazumifolia</i> and <i>Helicteres baruensis</i> (Sterculiaceae): two sympatric species from the Costa Rican tropical dry forest”, Rev. Biol. Trop., vol. 57, no. S1, pp. 161–177, Nov. 2009.