On the Councils  
   L. Pullan translation. With notes. If you wish to read an introduction, use the link for "previous". From the Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. 9.
   http://www.ccel.org/fathers2/NPNF2-09/Npnf2-09-06.htm

On the Trinity  
   E.W. Watson translation. Each of the twelve books in its own file, with notes and links to contents, previous, next.
   http://www.ccel.org/fathers2/NPNF2-09/Npnf2-09-07.htm