Verkerk, U. H., Siu, C. K., Steill, J. D., El Aribi, H., Zhao, J., Rodriquez, C. F.
, Oomens, J., Hopkinson, A. C., & Siu, K. W. M. (2010).
a2 ion derived from triglycine: an N1-protonated 4-imidazolidinone.
The Journal of Physical Chemistry Letters,
1(5), 868-872.
https://doi.org/10.1021/jz900464a