Gallego R, Codony-Servat J, Garcia-Albeniz X, Carcereny E, Longaron R, Oliveras A, Tosca M, Auge JM, Gascon P, Maurel J. Serum IGF-I, IGFBP-3, and matrix metalloproteinase-7 levels and acquired chemo-resistance in advanced colorectal cancer. Endocr Relat Cancer. 2009 Mar;16(1):311-7. doi: 10.1677/ERC-08-0250
Britt (DiBenedetti) DM, Collins FL, Cohen LM. Cigarette smoking and chewing gum use among college students. J Appl Biobehav Res. 2007 Jun 4;4(2):85-90. doi: 10.1111/j.1751-9861.1999.tb00057.x