Ordnance Survey - The UK government agency responsible for the official, definitive topographic survey and mapping of Great Britain. Cadastral Survey Reference Page - Survey information for the Land Surveyor involved in the survey and retracement of the Public Land Survey System Land Surveyor Reference Page - Reference materials that include State rules and regulations, continuing education requirements, seminars, and surveying companies. Earth Attributes - Aerial photography, land surveying, GIS and photogrammetric mapping services. Land Surveying - Introduction to the profession, with links to equipment, software, and books for sale. Wikipedia: Surveying - Overview of history of the profession, with articles on techniques, equipment, types of surveys and references submitted by the public. ASA Engineering and Surveying, Inc. - Provides topographic, ALTA, boundary and other surveying and mapping services. Valdosta, Georgia, USA.