APA استشهاد

HITCHCOCK A.S. (1950). MANUAL OF THE GRASSES OF THE UNITED STATES (2.). GOVERNMENT PRINTING OFFICE.

استشهاد بنمط شيكاغو

HITCHCOCK A.S. MANUAL OF THE GRASSES OF THE UNITED STATES. 2. WASHINGTON: GOVERNMENT PRINTING OFFICE, 1950.

MLA استشهاد

HITCHCOCK A.S. MANUAL OF THE GRASSES OF THE UNITED STATES. 2. GOVERNMENT PRINTING OFFICE, 1950.