1. Adams , G.W. Joint refraction experiment USGS and NGS, May 1, 1981 to June 16, 1981 Natl. Geod. Surv., Natl. Oceanic and Atmos. Admin. Washington, D.C. 1981
2. Precise leveling in the United States 1900-1903, with a readjustment of the level net and resulting elevations;Hayford;U.S. Coast and Geod. Surv. Rep, for 1903, App.,1904