The Master’s Seminary Faculty Lecture Series for 2013 dealt with the subject of the Trinity or Triunity of God. The lectures delved into specialized aspects of trinitarian theology not the major biblical and theological arguments related to trinitarianism. Part One of this bibliography fills that void with a listing of the key systematic theologies. Millard Erickson is, in our opinion, the most readable and thorough dealing with the main theological positions. Charles Hodge is a classic work; however, if one does not have facility in ecclesiastical Latin its value diminishes. Chafer is also thorough and detailed, being strong in his inductive method. This bibliography is certainly not exhaustive but designed rather to stimulate the reader to further study and serve as a starting point in research.