APA引文

(2018). National geographic almanac 2019: Hot new science, incredible photographs, maps, facts, infographics & more (U.S. edition.). National Geographic.

Chicago Style (17th ed.) Citation

National Geographic Almanac 2019: Hot New Science, Incredible Photographs, Maps, Facts, Infographics & More. U.S. edition. Washington, D.C.: National Geographic, 2018.

MLA引文

National Geographic Almanac 2019: Hot New Science, Incredible Photographs, Maps, Facts, Infographics & More. U.S. edition. National Geographic, 2018.

警告：這些引文格式不一定是100％准確.