| Literature DB >> 7252372 |
Abstract
The existence of periodic solutions of the equation (see formula in text) is established. This equation arises in the study of the spread of a disease which does not induce permanent immunity.Mesh:
Year: 1980 PMID: 7252372 DOI: 10.1007/bf00276986
Source DB: PubMed Journal: J Math Biol ISSN: 0303-6812 Impact factor: 2.259