da Cruz, Leonardo P. C.; Torregrosa, Joan Bifurcation of limit cycles in piecewise quadratic differential systems with an invariant straight line. (English) Zbl 1503.34088 J. Math. Anal. Appl. 514, No. 1, Article ID 126256, 17 p. (2022). Reviewer: Joan C. Artés (Barcelona) MSC: 34C23 34C05 34C07 34A36 34C45 × Cite Format Result Cite Review PDF Full Text: DOI arXiv OA License
Liang, Haihua; Torregrosa, Joan Weak-foci of high order and cyclicity. (English) Zbl 1396.34018 Qual. Theory Dyn. Syst. 16, No. 2, 235-248 (2017). Reviewer: Klaus R. Schneider (Berlin) MSC: 34C07 34C23 34C05 × Cite Format Result Cite Review PDF Full Text: DOI Link
Llibre, Jaume; Schlomiuk, Dana The geometry of quadratic differential systems with a weak focus of third order. (English) Zbl 1058.34034 Can. J. Math. 56, No. 2, 310-343 (2004). Reviewer: Valery A. Gaiko (Minsk) MSC: 34C07 34C40 34A26 14D05 × Cite Format Result Cite Review PDF Full Text: DOI
Zhang, Pingguang Uniqueness of the limit cycles of quadratic systems with a second-order weak focus. (Chinese. English summary) Zbl 1024.34023 Acta Math. Sin. 42, No. 2, 289-304 (1999). MSC: 34C05 × Cite Format Result Cite Review PDF
Gasull, Armengol; Torregrosa, Joan Small-amplitude limit cycles in Liénard systems via multiplicity. (English) Zbl 0947.34014 J. Differ. Equations 159, No. 1, 186-211 (1999). Reviewer: C.Chicone (Columbia) MSC: 34C07 34C05 × Cite Format Result Cite Review PDF Full Text: DOI
Lu, Gang; Liang, Zhaojun Non-existence of singular cycles in a quadratic differential system with fine focus of order three. (English) Zbl 0807.34036 Syst. Sci. Math. Sci. 7, No. 2, 133-139 (1994). Reviewer: Ye Yanqian (Nanjing) MSC: 34C05 × Cite Format Result Cite Review PDF
Chen, Weifeng A quadratic system with second-order weak focus. (Chinese. English summary) Zbl 0593.34035 Chin. Ann. Math., Ser. A 7, 201-211 (1986). MSC: 34C05 × Cite Format Result Cite Review PDF