These are the Blackwell Companions to theology (free to view),
Blackwell Companion to the Theologians. 2 Vols. Ed. Ian S. Markham. John Wiley and Sons, 2009.
Blackwell Companion to Modern Theology. S. Gareth J. Jones, ed. Wiley-Blackwell, 2004.
Blackwell Companion to Political Theology. Ed. Peter Scott, William T. Cavanaugh. Wiley-Blackwell, 2004.
Blackwell Companion to Postmodern Theology. Graham Ward, ed. Wiley-Blackwell, 2001.
Blackwell Encyclopedia of Modern Christian Thought. Alister E. McGrath, Duncan Forrester, eds. Wiley-Blackwell, 1995.
