I have code that is giving me the same results as these two sites

http://rl.se/sub-solar-point
http://www.skymarvels.com/infopages/vids/Earth%20-%20Sub-lunar%20Point%20001.htm

I want to compare to some authoritative resource.

aa.usno.navy.mil/data is down though and I'm not sure it would have such data to begin with?