@article{03684036, title = {Wronskians and subspaces of certain fourth order differential equations.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {3}, year = {1980}, pages = {275-292}, doi = {10.1155/S0161171280000208}, zbl = {0438.34024}, language = {en}, url = {http://dml.mathdoc.fr/item/03684036} }
Etgen, G.J.; Taylor jun., W.E. Wronskians and subspaces of certain fourth order differential equations.. International Journal of Mathematics and Mathematical Sciences, Tome 3 (1980) pp. 275-292. doi : 10.1155/S0161171280000208. http://gdmltest.u-ga.fr/item/03684036/