Formation, Isomerization, and Dissociation of alpha-Carbon-Centered and pi-Centered Glycylglycyltryptophan Radical Cations, 
Ng, Dominic C. M., Song T., Siu S. O., Siu C. K., Laskin J., and Chu Ivan K. 
, Journal of Physical Chemistry B, Volume 114, Issue 6, (2010)
 Abstract