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
Cohen LM, Britt DM, Collins FL, Stott HD, Carter LC. Chewing gum affects smoking topography. Exp Clin Psychopharmacol. 1999 Nov 1;7(4):444-7.