Vande Vere, E. K. (1979). Rugged heart: The story of George I. Butler. Southern Publishing Association.
Citazione stile Chigago Style (17a edizione)Vande Vere, Emmett K. Rugged Heart: The Story of George I. Butler. Nashville, TN: Southern Publishing Association, 1979.
Citatione MLA (9a ed.)Vande Vere, Emmett K. Rugged Heart: The Story of George I. Butler. Southern Publishing Association, 1979.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.