On the number of closed solutions for polynomial ODE's and a special case of Hilbert's 16th problem

On the number of closed solutions for polynomial ODE's and a special case of Hilbert's 16th problem / M. Calanchi, B. Ruf. - In: ADVANCES IN DIFFERENTIAL EQUATIONS. - ISSN 1079-9389. - 2:2(2002), pp. 197-216.