（1）标题：Simulation of electron density maps for two-dimensional crystal structures using Mathematica.  作者：Delatorre, Plinio,de Azevedo Jr., Walter Filgueira  来源：Journal of Applied Crystallography (Wiley-Blackwell)  日期：2001  出版物类型：Academic Journal
（2）作者：Zumberge, J. F., and W. I. Bettiger, 标题：Ephemeris and Clock Navigation Message Accuracy, in Global Positioning System - Theory and Applications, vol. I, edited by B. W.Parkinson and J. J. Spilker, 来源：585-599, Am. Inst. of Aeronautics and Astronautics, Inc., Washington, D.C., 1996'
（3）作者：Melbourne, W. G.,
标题：Sounding the Earth's atmosphere and ionospherew ith GPS,
来源：Eos AGU Trans., 76 (,16), 465-466, 1995.

（4）作者：Blewitt, G.,
标题：Carrier phase ambiguity resolution for the Global Positioning System applied to geodetic baselines up to 2000 km,
来源：J. Geophys. Res., 9• 10,187-10,283, 1989.