Winston, B. J. (1991). Geography: Our country and our world. Scott, Foresman and Co..
Lua i Stíl Chicago (17ú heag.)Winston, Barbara J. Geography: Our Country and Our World. Glenview: Scott, Foresman and Co., 1991.
Lua MLA (9ú heag.)Winston, Barbara J. Geography: Our Country and Our World. Scott, Foresman and Co., 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.