APA استشهاد

Janet I Sprent. (1987). The ecology of the Nitrogen cycle. Cambridge University press.

استشهاد بنمط شيكاغو

Janet I Sprent. The Ecology of the Nitrogen Cycle. Cambridge: Cambridge University press, 1987.

MLA استشهاد

Janet I Sprent. The Ecology of the Nitrogen Cycle. Cambridge University press, 1987.