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@article{PIM_1977_N_S_21_35_a22, author = {\v{Z}arko Mijajlovi\'c}, title = {A {Note} {On} {Elementary} {And} {Extension}}, journal = {Publications de l'Institut Math\'ematique}, pages = {141 }, publisher = {mathdoc}, volume = {_N_S_21}, number = {35}, year = {1977}, url = {http://geodesic.mathdoc.fr/item/PIM_1977_N_S_21_35_a22/} }
Žarko Mijajlović. A Note On Elementary And Extension. Publications de l'Institut Mathématique, _N_S_21 (1977) no. 35, p. 141 . http://geodesic.mathdoc.fr/item/PIM_1977_N_S_21_35_a22/