Allison, M. ., O’Leary, S. ., Lindley, M. ., Crane, L. ., Hurley, L. ., Beaty, B. ., … Kempe, A. . (1969). Financing of Vaccine Delivery in Primary Care Practices. Academic Pediatrics, 17(7), 770-777. https://doi.org/10.1016/j.acap.2017.06.001 (Original work published 1969)