PATOGENISITAS ISOLAT Escherichia con POSITIF CONGO RED PADA TELUR AYAM BEREMBRIO UMUR 12 HARI = PATOGENICITY OF CONGO RED POSITIVE ISOLATE OF Escherichia coil IN THE 12-DAYS OLD CHICKEN EMBRYOS - Perpustakaan UGM, i-lib ([Yogyakarta] : Universitas Gadjah Mada, 2002)