"By the end of the middle ages estimates of the number of Jews living in Zamora are between 1200 and 1300, an important figure considering that the entire city had between 6000 and 6500 inhabitants. It is evident that the Jewish population was significant, particularly from a demographic and economical perspective"
M. F. Ladero Quesada, "The expulsion of the Jews was one of the causes for the decay of Zamora" La Opinión, Julio, 2006
Other references from the same author: "Notes on the history of Jews and Conversos in Zamora in the Middle Ages" (13th - 15th centuries), Sefarad Journal,
48:1, 1988, p.40.