Voir la notice de l'article provenant de la source Library of Science
@article{PMF_1933_40_1_a7, author = {Biernacki, M.}, title = {Sur l'\'equation diff\'erentielle {x''+A(t)x=0}}, journal = {Prace Matematyczno-Fizyczne}, pages = {163--171}, publisher = {mathdoc}, volume = {40}, number = {1}, year = {1933}, language = {fr}, url = {http://geodesic.mathdoc.fr/item/PMF_1933_40_1_a7/} }
Biernacki, M. Sur l'équation différentielle x''+A(t)x=0. Prace Matematyczno-Fizyczne, Tome 40 (1933) no. 1, pp. 163-171. http://geodesic.mathdoc.fr/item/PMF_1933_40_1_a7/