@article{GDZPPN002550059, title = {Strong normality and normality for difference fields.}, journal = {Aequationes mathematicae}, volume = {20}, year = {1980}, pages = {159-165}, zbl = {0459.12018}, url = {http://dml.mathdoc.fr/item/GDZPPN002550059} }
Infante, Ronald P. Strong normality and normality for difference fields.. Aequationes mathematicae, Tome 20 (1980) pp. 159-165. http://gdmltest.u-ga.fr/item/GDZPPN002550059/