1. Baldwin , The Mediaeval Church, p. 29
2. The Mediaeval Church
3. Fischer , “Feudal Europe, 800–1300,” p. 438, for the citation in my own work
4. Fischer , “Feudal Europe, 800–1300,” p. 431
5. Ruggie , “Continuity and Transformation in the World Polity,” pp. 274–75