Lawrence Perko

Local bifurcations and a survey of bounded quadratic systems

Freddy Dumortier, L. Perko, F. Dumortier, 2000 .

Higher Order Bifurcations of Limit Cycles

Iliya D. Iliev, L. Perko, I. Iliev, 1999 .

MULTIPLE LIMIT CYCLE BIFURCATION SURFACES AND GLOBAL FAMILIES OF MULTIPLE LIMIT CYCLES

Lawrence Perko, 1995 .