Rutgers, L.V.; van Strydonck, M.; Boudin, M.; van der Linde, C. (2009). «Stable isotope data from the early Christian catacombs of ancient Rome: new insights into the dietary habits of Rome's early Christians». Journal of Archaeological Science36 (5): 1127–1134. doi:10.1016/j.jas.2008.12.015. ISSN0305-4403.
Rutgers, L.V.; van Strydonck, M.; Boudin, M.; van der Linde, C. (2009). «Stable isotope data from the early Christian catacombs of ancient Rome: new insights into the dietary habits of Rome's early Christians». Journal of Archaeological Science36 (5): 1127–1134. doi:10.1016/j.jas.2008.12.015. ISSN0305-4403.