Faig, Wolfgang and Fritz Deumlich. Surveying Instruments. Berlin, Boston: De Gruyter, 1982. Web. Retrieved 26 May. 2013, from http://www.degruyter.com/view/product/9836

Faig, W. & Deumlich, F. (1982). Surveying Instruments. Berlin, Boston: De Gruyter. Retrieved 26 May. 2013, from http://www.degruyter.com/view/product/9836

Faig, Wolfgang and Fritz Deumlich. 1982. Surveying Instruments. Berlin, Boston: De Gruyter. Retrieved 26 May. 2013, from http://www.degruyter.com/view/product/9836