@article{:/content/10.2807/esw.05.21.01747-en, author = "Noah, N and Ramsay, M and Twisselmann, B", title = "Imported cases of polio in Bulgaria – vaccination campaign postponed", journal = "Weekly releases (1997–2007)", year = "2001", volume = "5", number = "21", eid = 1747, pages = "", url = "https://www.eurosurveillance.org/content/10.2807/esw.05.21.01747-en", doi = "https://doi.org/10.2807/esw.05.21.01747-en" }