@article{135111,
      recid = {135111},
      author = {Hartsock, Peter. and Genser, Sander G.},
      title = {Longitudinal studies of HIV infection in intravenous drug  users : methodological issues in natural history research  /},
      publisher = {U.S. Dept. of Health and Human Services, Public Health  Service, Alcohol, Drug Abuse, and Mental Health  Administration, National Institute on Drug Abuse ;},
      address = {Rockville, MD :},
      pages = {iv, 153 p. :},
      year = {1991},
      url = {http://library.usi.edu/record/135111},
}