@article{02096932,
title = {Sturm-Liouville and focal higher order BVPs with singularities in phase variables.},
journal = {Georgian Mathematical Journal},
volume = {10},
year = {2003},
pages = {165-191},
zbl = {1069.34029},
language = {en},
url = {http://dml.mathdoc.fr/item/02096932}
}
Rachůnková, Irena; Staněk, Svatoslav. Sturm-Liouville and focal higher order BVPs with singularities in phase variables.. Georgian Mathematical Journal, Tome 10 (2003) pp. 165-191. http://gdmltest.u-ga.fr/item/02096932/