1. Struktur und Funktion des Velamen Radicum der Orchideen;Barthlott,1976
2. The life history profile of Tillandsia circinnata (Bromeliaceae) and the rarity of extreme epiphytism among the angiosperms;Benzing;Selbyana,1978
3. Functional correlates of deciduousness in Catasetum integerrimum (Orchidaceae);Benzing;Selbyana,1982