Παραπομπή APA

Westerman, R. L., Westerman, R. L., & Westerman, R. L. (1990). Soil testing and plant analysis (3rd ed.). Madison: Soil Science Society of America.

Παραπομπή Chicago Style

Westerman, Robert Lee, Robert Lee Westerman, and R. L. Westerman. Soil Testing and Plant Analysis. 3rd ed. Madison: Soil Science Society of America, 1990.

Παραπομπή MLA

Westerman, Robert Lee, Robert Lee Westerman, and R. L. Westerman. Soil Testing and Plant Analysis. 3rd ed. Madison: Soil Science Society of America, 1990.

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