O.  Lachenaud and Jongkind, C., ?Three new or little-known Chassalia (Rubiaceae) species from west and central Africa?, Nordic Journal of Botany, vol.  28, p. 20, 2010.

M.  Cheek and Lachenaud, O., ?Psychotria elephantina sp. nov. (Rubiaceae) an endangered rainforest shrub from Cameroon?,  Nordic Journal of Botany, vol. 31, p. 573, 2013.