Não informado. (1990). Geo info systems. Advanstar Communications.
Style de citation Chicago (17e éd.)Não informado. Geo Info Systems. Duluth, Minn: Advanstar Communications, 1990.
Style de citation MLA (8e éd.)Não informado. Geo Info Systems. Advanstar Communications, 1990.
Attention : ces citations peuvent ne pas être correctes à 100%.