Like Rock 34 I have no particular reference to point at, and being BAe in an earlier life I've never had to get involved in real fighting.
However lots of books mention the 3:1 ratio as the standard necessity for any invading / overtaking force - one source which might suit your needs is ' One Hundred Days ' by Admiral Sandy Woodward, re. the Falklands 1982.
Good luck with the O.U, and this may be an aviation site, but it ain't light blue, plenty of FAA & Army aviators around !
DZ