1. Baas, P. 1972. Anatomical contributions to plant taxonomy. II. The affinitiesof Hua Pierre andAfrostyrax Perkins et Gilg. Blumea20: 161–192.
2. — 1974. Stomatal types in Icacinaceae. Additional observations on genera outside Malesia. Acta Bot. Neerl.23: 193–200.
3. — 1975. Vegetative anatomy and the affinities of Aquifoliaceae,Sphenostemon, Phelline andOncotheca. Blumea22: 311–407.
4. — &R. Kool. 1983. Comparative leaf anatomy ofHeisteria (Olacaceae). Blumea28: 367–388.
5. Bailey, I. W. &C. G. Nast. 1945. Morphology and relationships ofTrochodendron andTetracentron. I. Stem, root, and leaf. J. Arnold Arbor.26: 143–154.