1. J. E. R. Ross, “Geodetic Problems of Shoran”, Pub. 78, Geodetic Survey of Canada, 1955.
2. H. F. Rainsford, “Survey Adjustments and Least Squares”, Constable (London), 1957.
3. A. G. Bomford, “Varycord, A Fortran Program for the Least Squares Adjustment of Horizontal Control Surveys”, Technical Report No.6, Division of National Mapping, Canberra, 1967.
4. T. Vincenty, “Proposal for Combined Adjustments of Dissimilar Quantities in Horizontal Surveys”, 1381st Geodetic Survey Squadron, United States Air Force, 1967.