Washington State University. Cooperative Extension & United States. Department of Agriculture. (2001). Perennials for the Inland Northwest (Rev. Sept. 2001.). Washington State University Cooperative Extension ; U.S. Dept. of Agriculture.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Washington State University. Cooperative Extension و United States. Department of Agriculture. Perennials for the Inland Northwest. Rev. Sept. 2001. [Pullman, Wash.] : [Washington, D.C.]: Washington State University Cooperative Extension ; U.S. Dept. of Agriculture, 2001.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Washington State University. Cooperative Extension و United States. Department of Agriculture. Perennials for the Inland Northwest. Rev. Sept. 2001. Washington State University Cooperative Extension ; U.S. Dept. of Agriculture, 2001.