R, B. L. (1992). Tantangan masalah lingkungan hidup. Yayasan Obor Indonesia.
Chicago Style (17th ed.) CitationR, Brown Lester. Tantangan Masalah Lingkungan Hidup. Yayasan Obor Indonesia, 1992.
MLA (8th ed.) CitationR, Brown Lester. Tantangan Masalah Lingkungan Hidup. Yayasan Obor Indonesia, 1992.
Warning: These citations may not always be 100% accurate.