.American Congress on Surveying and Mapping ( 38th : 1978 : Wash. )：Proceedings of the American Congress on Surveying and Mapping 38th Annual Meeting, Wash., 1978.,1978.
American Congress on Surveying and Mapping ( 38th : 1978 : Wash. )：Proceedings of the American Congress on Surveying and Mapping 38th Annual Meeting, Wash., 1978
