1. API Bulletin D20 Directional drilling survey calculation methods and terminology;API,1985
2. SY/T 5435-2012 Wellpath planning & trajectory calculation for directional wells;National Energy Administration,2012
3. A systematic approach to well surveying calculations;Taylor;SPE Journal,1972
4. Directional survey by the circular arc method;Zaremba;SPE Journal,1973
5. Computing accurate directional surveys;Blythe;World Oil,1975