Perihelion of Mercury with classical mechanics ?

1. Does anyone know if the classical calculation of the perihelion of
Mercury accounts for the attraction of the sun by Mercury?

I stumbled on an interesting article that discusses flaws in Newton's
theory, and which suggests that the sun's motion is neglected even for
the most accurate calculations.
It would be surprising if that were true!

2. It also suggests that when taking it into account, the correct
answer may be found. Any ideas if htat could be right?
http://www.journaloftheoretics.com/L...pers/gravi.pdf
Regretfully I know nothing about astronomy.

Harald