Letter from A. Hansen 28.6.82; Index Herbariorum, ed. 8 from R.E.G. Pichi Sermolli 1 March 1991. Date of death from M. Kovanda in letter of 9 February 1998. See also Wiadom. Bot., 52(1-2): 52 (2008).Biogr. details incl. portr. in Orchidac. W.-Centr. Africa, 1: 8-9 (2010).