F.  Gagnepain, ?Treize orchidacées nouvelles d'Indo-Chine?, Bull. Mus. Natl. Hist., Paris, 2. Sér., vol. 3, pp. 679 - 687, 1931.

J. J.  Smith, ?On a collection of Orchidaceae from Central Borneo?, Bull. Jard. Bot. Buitenzorg, ser. 3, vol. 11, pp. 83 - 160, 1931.

H.  Honda, ?Nuntia ad floram Japoniae XIV?, Bot. Mag. (Tokyo), vol. 45, pp. 469 - 471, 1931.

J. E.  Dandy, ?Some new names in the Monocotyledons - I?, Journal of Botany, British and Foreign, vol. 69, pp. 53 - 55, 1931.

N. Y.  Sandwith, ?Contributions to the flora of tropical America. Saprophytes collected by the Oxford University Expedition to British Guiana, 1929?, Bull. Misc. Inform., vol. 1931, pp. 46 - 61, 1931.