Geodesic
Quadratic systems with limit cycles of normal size
Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica, no. 1 (2003), pp. 31-46.

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In the class of planar autonomous quadratic polynomial differential systems we provide 6 different phase portraits having exactly 3 limit cycles surrounding a focus, 5 of them have a unique focus. we also provide 2 different phase portraits having exactly 3 limit cycles surrounding one focus and 1 limit cycle surrounding another focus. the existence of the exact given number of limit cycles is proved using the dulac function. all limit cycles of the given systems can be detected through numerical methods; i.e. the limit cycles have “a normal size” using perko's terminology. 
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Leonid A. Cherkas; Joan C. Artés; Jaume Llibre. Quadratic  systems with limit cycles of normal size. Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica, no. 1 (2003), pp. 31-46. https://geodesic-test.mathdoc.fr/item/BASM_2003_1_a3/

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