ŞUBĂ A, TURUTA S. CUBIC DIFFERENTIAL SYSTEMS WITH A WEAK FOCUS AND A REAL INVARIANT STRAIGHT LINE OF MAXIMAL ALGEBRAIC MULTIPLICITY . ActaEX [Internet]. 2019Jul.9 [cited 2024Oct.16];4(2):119-30. Available from: https://revistaust.upsc.md/index.php/acta_exacte/article/view/359