PERINGATAN DINI PENCEMARAN LOGAM BERAT DAN PESTISIDA BERDASARKAN RASIO SEKS ANAKAN Daphnia sp. =EARLY WARNING SYSTEM FOR HEAVY METAL AND PESTICIDE POLLUTION BASED ON THE SEX RATIO OF Daphnia sp. OFFSPRING - Perpustakaan UGM, i-lib ([Yogyakarta] : Universitas Gadjah Mada, 2009)