Symons, L. (1967). Agricultural geography. Bell.
Lua i Stíl Chicago (17ú heag.)Symons, Leslie. Agricultural Geography. London: Bell, 1967.
Lua MLA (9ú heag.)Symons, Leslie. Agricultural Geography. Bell, 1967.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.