Erenstein, HG, Browne, D, Curtin, S, Dwyer, RS, Higgins, RN, Hommel, SF, Menzinga, J, Pires Jorge, JA, Sauty, M, de Vries, G, England, A, "The validity and reliability of the exposure index as a metric for estimating the radiation dose to the patient", Radiography, 2020