Schwartz, S. H., Spring, B., & Spring, I. (1983). Nature in the Northwest: An introduction to the natural history and ecology of the northwestern United States from the Rockies to the Pacific. Prentice-Hall.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Schwartz, Susan H., Bob Spring, و Ira Spring. Nature in the Northwest: An Introduction to the Natural History and Ecology of the Northwestern United States from the Rockies to the Pacific. Englewood Cliffs, N.J.: Prentice-Hall, 1983.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Schwartz, Susan H., et al. Nature in the Northwest: An Introduction to the Natural History and Ecology of the Northwestern United States from the Rockies to the Pacific. Prentice-Hall, 1983.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.