For further reading:
Bloembergen, N., E. M. Purcell, and R. V. Pound. "Relaxation Effects in Nuclear Magnetic Resonance Absorption." Physical Review 73 (1948): 679-712.
A classic relaxation paper.
Hahn, E. L. "Spin Echos." Physical Review 80 (1950): 580-594.
The first paper to describe the spin echo phenomenon.
Wedeen, V. J., P. Hagmann, W. Y. Tseng, T. G. Reese, and R. M. Weisskoff. "Mapping complex tissue architecture with diffusion spectrum magnetic resonance imaging." Magnetic Resonance in Medicine 54 (2005): 1377-86.
Savoy, R. L. "History and future directions of human brain mapping and functional neuroimaging." Acta Psychologica 107 (2001): 9-42.
Savoy, R. L. "Functional Magnetic Resonance Imaging (fMRI)." Encyclopedia of Neuroscience. 2nd ed. Boston, MA: Birkhauser, 1996.
Savoy, Robert L. "Experimental design in brain activation MRI: Cautionary tales." Brain Research Bulletin 67 (2005): 361–367.
Savoy, Robert L. "Using Small Numbers of Subjects in fMRI-Based Research." IEEE Engineering in Medicine and Biology Magazine 25 (2006): 52-59.