A Unified Mathematical Language for Physics and Engineering (1996) [pdf] 12 years ago
My resident core-stability expert (who might now have to learn about GA) alerted me to this thread. Can't say how happy I am that people are looking at it -- am happy even with the useful criticisms (have just emailed the link to the other Lasenbys, Doran, Dorst, Hestenes). Another similar semi-popular IEEE article (without equations) will appear soon.