APA (7th ed.) Citation

Köhlein, F., & Jermyn, J. (1991). Gentians. Christopher Helm ; Timber Pr.

Chicago Style (17th ed.) Citation

Köhlein, Fritz, and Jim Jermyn. Gentians. London : Portland, Ore: Christopher Helm ; Timber Pr, 1991.

MLA (9th ed.) Citation

Köhlein, Fritz, and Jim Jermyn. Gentians. Christopher Helm ; Timber Pr, 1991.