This document may be downloaded, read, stored and printed for your own use within the limits of § 53 UrhG but it may not be distributed via the internet or passed on to external parties.Dieses Dokument darf im Rahmen von § 53 UrhG zum eigenen Gebrauch kostenfrei heruntergeladen, gelesen, gespeichert und ausgedruckt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.Schneider, Klaus R.Grin, Alexander2022-06-232022-06-232019https://oa.tib.eu/renate/handle/123456789/9222https://doi.org/10.34657/8260We consider autonomous systems with cylindrical phase space. Lower and upper bounds for the number of limit cycles surrounding the cylinder can be obtained by means of an appropriate Dulac-Cherkas function. We present different possibilities to improve these bounds including the case that the exact number of limit cycles can be determined. These approaches are based on the use of several Dulac-Cherkas functions or on applying some factorized Dulac function.eng510Autonomous systems with cylindrical phase spacelocation and number of limit cycles of second kindDulac--Cherkas functionfactorized Dulac functionReport16 S.