Facile Synthesis of Symmetric and Unsymmetric 1,3,4-Oxadiazoles Using 2-Acyl(or aroyl)pyridazin-3-ones - Park, Yong-Dae; Kim, Jeum-Jong; Chung, Hyun-A; Kweon, Deok-Heon; Cho, Su-Dong; Lee, Sang-Gyeong; Yoon, Yong-Jin (Synthesis, 2003)