APA (7th ed.) Citation

Moll, J. W., & Janssonius, H. H. (1923). Botanical pen-portraits. M. Nijhoff.

Chicago Style (17th ed.) Citation

Moll, J. W., and Hindrik Haijo Janssonius. Botanical Pen-portraits. The Hague: M. Nijhoff, 1923.

MLA (9th ed.) Citation

Moll, J. W., and Hindrik Haijo Janssonius. Botanical Pen-portraits. M. Nijhoff, 1923.