Bayer Patent: DE2639748BE858362 , 19781978 ; Chem.Abstr., 1979 , vol. 90, # 151849 Full Text Show Details Bayer AG Patent: DE2657772 , 1978 ; Chem.Abstr., 1978 , vol. 89, # 108756 Full Text Show Details Bayer Patent: DE2730620 , 1979 ; Chem.Abstr., 1979 , vol. 90, # 151852