Abler , R., & Alber, R. .. ,. (1975). Human geography in a shrinking world: By Ronald Abler , Donald Janelle , Allen Philbrick and John Sommer. Duxbury.
Chicago-viite (17. p.)Abler , Ronald, ja Ronald . ,,, Alber. Human Geography in a Shrinking World: By Ronald Abler , Donald Janelle , Allen Philbrick and John Sommer. Massachusetts: Duxbury, 1975.
MLA-viite (9. p.)Abler , Ronald, ja Ronald . ,,, Alber. Human Geography in a Shrinking World: By Ronald Abler , Donald Janelle , Allen Philbrick and John Sommer. Duxbury, 1975.
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