Παραπομπή APA

Xu, G., & Chen, Y. (1999). Towards digital earth: Proceedings of the International Symposium on Digital Earth. Beijing: Science Press.

Παραπομπή Chicago Style

Xu, Guanhua, and Yuntai Chen. Towards Digital Earth: Proceedings of the International Symposium On Digital Earth. Beijing: Science Press, 1999.

Παραπομπή MLA

Xu, Guanhua, and Yuntai Chen. Towards Digital Earth: Proceedings of the International Symposium On Digital Earth. Beijing: Science Press, 1999.

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