Liu J, Cohen RA, Gongvatana A, Sheinkopf SJ, Lester BM. Impact of Prenatal Exposure to Cocaine and Tobacco on Diffusion Tensor Imaging and Sensation Seeking in Adolescents. The Journal of Pediatrics. 2011 Nov;159(5):771–5. doi: 10.1016/j.jpeds.2011.05.020.