Hurley, L., Allison, M., Pilishvili, T., O’Leary, S., Crane, L., Brtnikova, M., … Kempe, A. (1969). Primary Care Physicians’ Struggle with Current Adult Pneumococcal Vaccine Recommendations. Journal of the American Board of Family Medicine : JABFM, 31(1), 94-104. https://doi.org/10.3122/jabfm.2018.01.170216 (Original work published 1969)