European Conference on Geographical Information Systems Brussels, Scholten, H. J., Harts, J., & Ottens, H. F. L. (1991). EGIS '91: Proceedings : second European Conference on Geographical Information Systems, Brussels, Belgium April 2-5, 1991. EGIS Foundation.
芝加哥风格引文European Conference on Geographical Information Systems Brussels, H. J. Scholten, JanJaap Harts, 与 Henk F. L. Ottens. EGIS '91: Proceedings : Second European Conference on Geographical Information Systems, Brussels, Belgium April 2-5, 1991. Utrecht, Netherlands: EGIS Foundation, 1991.
MLA引文European Conference on Geographical Information Systems Brussels, et al. EGIS '91: Proceedings : Second European Conference on Geographical Information Systems, Brussels, Belgium April 2-5, 1991. EGIS Foundation, 1991.