Aktivitas Enzim Nitrat Reduktase dan Korelasinya Terhadap Sifat Pertumbuhan Tanaman Kakao (Theobroma cacao L.) Muda. (Nitrate Reductase Activity and Its Correlation With Growth Characteristics of Young Cocoa .. - Perpustakaan UGM, i-lib ([Yogyakarta] : Universitas Gadjah Mada, 1991)