Cofer, C.N., The history of the concept of motivation. Journal of the History of the Behavioral Sciences, 1981. 17 (1): p. 48–53.
126
Lee, W., et al., Neural differences between intrinsic reasons for doing versus extrinsic reasons for doing: An fMRI study. Neuroscience Research, 2012. 73 (1): p. 68–72.