An impairment in sniffing contributes to the olfactory impairment in Parkinson’s disease
Sobel, N., Thomason, M.E., Stappen, I., Tanner, C.M., Tetrud, J.W., Bower, J.M., and Gabrieli, J.D.E. (2001). Proceedings of the National Academy of Sciences of the United States of America, 98, 3495-3500.