@article{AHL_2020__3__615_0,
     author = {Gavrilov, Lubomir},
     title = {On the center-focus problem for the equation $\protect \frac{\protect \mathrm{d}y}{\protect \mathrm{d}x} + \Sigma _{i=1}^{n} a_i(x) y^i = 0, 0\le x \le 1$ where $a_i$ are polynomials},
     journal = {Annales Henri Lebesgue},
     pages = {615--648},
     publisher = {\'ENS Rennes},
     volume = {3},
     year = {2020},
     doi = {10.5802/ahl.41},
     language = {en},
     url = {https://ahl.centre-mersenne.org/articles/10.5802/ahl.41/}
}