[1]
Petrus, R., د., Jameel, G. and غادة 2006. The existence and convergence of the periodic solution of the system of complementary equations - nonlinear differential of the second class type Volterra. Journal of Education and Science (JES). 18, 1 (Jan. 2006), 124–137. DOI:https://doi.org/10.33899/edusj.2006.78661.