Hart, R. L. (2019). Glenhill Farm: The history of a family estate : as revealed in the correspondence between Brognard Okie and Ernst and Mary Behrend. Penn State Erie, the Behrend College.
Lua i Stíl Chicago (17ú heag.)Hart, Richard L. Glenhill Farm: The History of a Family Estate : As Revealed in the Correspondence Between Brognard Okie and Ernst and Mary Behrend. Erie, Pennsylvania: Penn State Erie, the Behrend College, 2019.
Lua MLA (9ú heag.)Hart, Richard L. Glenhill Farm: The History of a Family Estate : As Revealed in the Correspondence Between Brognard Okie and Ernst and Mary Behrend. Penn State Erie, the Behrend College, 2019.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.