1. "Infectious Diseases of Humans: Dynamics and Control,";R. M. Anderson;Oxford Univ. Press,1991
2. Harnack's inequality for cooperative weakly coupled elliptic systems,;A. Arapostathis;Comm. Part. Diff. Eq.,1999
3. "Mathematical Models in Population Biology and Epidemiology,";F. Brauer;Springer,2000
4. "Vertically Transmitted Diseases,";S. Busenberg;Biomathematics volume 23,1993
5. "Mathematical Structures of Epidemic Systems,";V. Capasso;Lecture Notes in Biomathematics volume 97,1993