An Sist Sanit Navar. 2011 May-Aug;34(2):193-202. doi: 10.4321/s1137-66272011000200006.
A Letter to the Editors, from George Gregory, M. D. Physician to the Small-Pox and Vaccination Hospital; Inclosing a Correspondence with Dr. Jenner on the Subject of Small-Pox after Vaccination.