Frye S, Crosby M, Edwards TP, Juliano R. US academic drug discovery. Nat Rev Drug Discov. 2011 Jun 1;10(6):409-10. doi: 10.1038/nrd3462
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