Cita APA (7a ed.)
U.S. Postal Service & U.S. Postal Service. Wildlife America: A collection of U.S. Commemorative Stamps.
Cita Chicago Style (17a ed.)
U.S. Postal Service y U.S. Postal Service. Wildlife America: A Collection of U.S. Commemorative Stamps.
Cita MLA (9a ed.)
U.S. Postal Service y U.S. Postal Service. Wildlife America: A Collection of U.S. Commemorative Stamps.
警告：這些引文格式不一定是100％准確.