TY  - JOUR
AU  - Iurie Calin
AU  - Stanislav Ciubotaru
TI  - The Lyapunov quantities and the center conditions for a~class of bidimensional polynomial systems of differential equations with nonlinearities of the fourth degree
JO  - Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica
PY  - 2017
SP  - 112
EP  - 130
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/BASM_2017_2_a8/
LA  - en
ID  - BASM_2017_2_a8
ER  -