@article{BASM_2006_3_a0,
     author = {O. V. Diaconescu and M. N. Popa},
     title = {Lie algebras of operators and invariant $GL(2,\mathbb{R})$-integrals for {Darboux} type differential systems},
     journal = {Buletinul Academiei de \c{S}tiin\c{t}e a Republicii Moldova. Matematica},
     pages = {3--16},
     publisher = {mathdoc},
     number = {3},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BASM_2006_3_a0/}
}