Citazione Stile APA (7a Edizione)

Johnston, I. M. (1929). Contributions from the Gray Herbarium of Harvard University. Harvard University.

Citazione stile Chigago Style (17a edizione)

Johnston, Ivan M. Contributions from the Gray Herbarium of Harvard University. Cambridge: Harvard University, 1929.

Citatione MLA (9a ed.)

Johnston, Ivan M. Contributions from the Gray Herbarium of Harvard University. Harvard University, 1929.