1. Le Mal de Naples: Histoire de la Syphilis;Quetel, C.,1986
2. International passenger survey 1993. Office of Population and Census
3. International travel and AIDS;Gilmore, N.; Orkin, A.J.; Duckett, M.; Grover, S.A.;AIDS,1989
4. International travel and sexually transmitted diseases;A, De Schryver; A, Meheus;Wld Hlth Statist Quart,1989
5. Centres for coordinating epidemiological studies of AIDS and HIV infection. Unlinked anonymous monitoring of HIV prevalence in England and Wales: 1990-92;Medical Research Council (UK;Communicable Disease Report,1993