Commentary on the Epistle to the Galatians by Martin Luther - A verse by verse commentary written in 1535. Part of Project Wittenberg and in the public domain. - http://www.iclnet.org/pub/resources/text/wittenberg/luther/gal/web/gal-inx.html
Commentary on the Epistle to the Galatians - T. Graebner translation in HTML. Divided into smaller sections within each chapter with internal links. - http://www.worldwideschool.org/library/books/relg/christiantheology/CommentaryontheEpistletotheGalatians/toc.html