Sharp L, Donnelly D, Hegarty A, Carsin AE, Deady S, McCluskey N, Gavin A, Comber H. Risk of several cancers is higher in urban areas after adjusting for socioeconomic status. Results from a two-country population-based study of 18 common cancers. J Urban Health. 2014 Jun;91(3):510-25. doi: 10.1007/s11524-013-9846-3
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.