Lawrence, P. (1992). Qualifications: Survey and mapping qualifications for the 1990s. London : British Cartographic Society.
Chicago-viite (17. p.)Lawrence, Peter. Qualifications: Survey and Mapping Qualifications for the 1990s. London : British Cartographic Society, 1992.
MLA-viite (9. p.)Lawrence, Peter. Qualifications: Survey and Mapping Qualifications for the 1990s. London : British Cartographic Society, 1992.
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