Oyama, M., & Takehara, H. Revised standard soil color charts.
Chicago Style (17th ed.) CitationOyama, Masatada, and Hideo Takehara. Revised Standard Soil Color Charts.
MLA (8th ed.) CitationOyama, Masatada, and Hideo Takehara. Revised Standard Soil Color Charts.
Warning: These citations may not always be 100% accurate.