APA

Davis P. H., Cullen J., . (1997). The identification of flowering plant families. Cambridge, England: Cambridge University.

Chicago

Davis P H, Cullen James, . 1997. The identification of flowering plant families. Cambridge, England: Cambridge University.

Harvard

Davis P. H., Cullen J., . (1997). The identification of flowering plant families. Cambridge, England: Cambridge University.

MLA

Davis P H, Cullen James, . The identification of flowering plant families. Cambridge, England: Cambridge University. 1997.