APA

Stebbins G. L., . (1974). Flowering plants: evolution above the species level. Cambridge, Mass: Belknap Press of Harvard University Press.

Chicago

Stebbins G Ledyard, . 1974. Flowering plants: evolution above the species level. Cambridge, Mass: Belknap Press of Harvard University Press.

Harvard

Stebbins G. L., . (1974). Flowering plants: evolution above the species level. Cambridge, Mass: Belknap Press of Harvard University Press.

MLA

Stebbins G Ledyard, . Flowering plants: evolution above the species level. Cambridge, Mass: Belknap Press of Harvard University Press. 1974.