Auslig geographic
calculation formulas> calculate distance between two lon/lat pairs, and
etc.
CorpsCom (US Army Topographic Engineering
Center) Transformation Software+ Other
Dr Math's Formula website -
Formulas for many types of geographic and trigonometric computations
"Geocentric Datum
of Australia - Technical Manual"> Lots of datum and other geodetic conversion
formulas
Mentor Software> Coordinate
Transformation and "Rubber Sheeting" Software
NimaMuse
Coordinate Transformation Software
OSGB coordinate
conversion to/from Lon/Lat using spread sheets