Jönsson, P.-G.; Kvick, Å. (1972). “Precision neutron diffraction structure determination of protein and nucleic acid components. III. The crystal and molecular structure of the amino acid α-glycine”. Acta Cryst. B,28: 1827–1833. doi:10.1107/S0567740872005096.
Price, William D.; Jockusch, Rebecca A.; Williams, Evan R. (1997). “Is Arginine a Zwitterion in the Gas Phase?”. J. Am. Chem. Soc.119 (49): 11988–11989. doi:10.1021/ja9711627.text
R. L. Sass (April 1960). “A neutron diffraction study on the crystal structure of sulfamic acid”. Acta Cryst.13 (4): 320–324. doi:10.1107/S0365110X60000789.
Price, William D.; Jockusch, Rebecca A.; Williams, Evan R. (1997). “Is Arginine a Zwitterion in the Gas Phase?”. J. Am. Chem. Soc.119 (49): 11988–11989. doi:10.1021/ja9711627.text
