Bernard, AM., Moreau, D., & Lauwerys, R. (1982). Comparison of Retinol-binding Protein and Beta-microglobulin Determination in Urine for the Early Detection of Tubular Proteinuria. Clinica Chimica Acta, 126(1), 1-7. https://doi.org/10.1016/0009-8981(82)90356-4 (Original work published 1982)