Edwards T, Cadigan RJ, Evans JP, Henderson GE. Biobanks containing clinical specimens: defining characteristics, policies, and practices. Clin Biochem. 2014 Mar;47(4-5):245-51. doi: 10.1016/j.clinbiochem.2013.11.023
Rothman KJ, Glass RL, Espinal F, Velez H. Caries-free teeth in the absence of fluoride ion. J Public Health Dent. 1972;32(4):225-8. doi: 10.1111/j.1752-7325.1972.tb03977.x