Edited by Estall, R. (1991). Global change and challenge: Geography for the 1990s. Routledge.
Chicago-čujuhus (17. p.)Edited by Estall, Robert. Global Change and Challenge: Geography for the 1990s. London: Routledge, 1991.
MLA-čujuhus (9. p.)Edited by Estall, Robert. Global Change and Challenge: Geography for the 1990s. Routledge, 1991.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.