APA

Purves R., Association for Computing Machinery, ACM Special Interest Group on Hypertext H. a. W. & ACM Special Interest Group on Information Retrieval. (2007). Proceedings of the 4th ACM workshop on Geographical information retrieval. New York, NY: ACM.

Chicago

Purves Ross, Association for Computing Machinery, ACM Special Interest Group on Hypertext Hypermedia and Web and ACM Special Interest Group on Information Retrieval. 2007. Proceedings of the 4th ACM workshop on Geographical information retrieval. New York, NY: ACM.

Harvard

Purves R., Association for Computing Machinery, ACM Special Interest Group on Hypertext H. a. W. and ACM Special Interest Group on Information Retrieval. (2007). Proceedings of the 4th ACM workshop on Geographical information retrieval. New York, NY: ACM.

MLA

Purves Ross, Association for Computing Machinery, ACM Special Interest Group on Hypertext Hypermedia and Web and ACM Special Interest Group on Information Retrieval. Proceedings of the 4th ACM workshop on Geographical information retrieval. New York, NY: ACM. 2007.