Real operator algebras, Bing-Ren Li, Pub. Co. Pte. Ltd, 2003 (and the bibliography in that book). Also the other operator algebra book by the same author has parts about real operator algebras (together with the traditional complex ones)
An older book is by Goodearl, and a classical paper is http://jlms.oxfordjournals.org/content/s2-47/1/97.full.pdf (and references in it).
You can also seacr for papers citing them: example1, example2