We apply diagram geometry and amalgam techniques to give a new proof of a theorem of K.-W. Phan, characterizing the special unitary group as a group generated by certain systems of subgroups SU(2, q(2)).
Available on publisher's site at http://www.degruyter.com/view/j/jgth.2004.7.issue-3/jgth.2004.010/jgth.2004.010.xml.
Bennett, C. D., Shpectorov, S. A New Proof of a Theorem of Phan, Journal of Group Theory. vol. 7 (2004) pp. 287-310.