Bridges, J. H. (1976). The life & work of Roger Bacon: An introduction to the Opus majus. Richwood Pub. Co..
Lua i Stíl Chicago (17ú heag.)Bridges, John Henry. The Life & Work of Roger Bacon: An Introduction to the Opus Majus. Merrick, N.Y.: Richwood Pub. Co., 1976.
Lua MLA (8ú heag.)Bridges, John Henry. The Life & Work of Roger Bacon: An Introduction to the Opus Majus. Richwood Pub. Co., 1976.
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