General Petit's Account of the Waterloo Campaign Smith, G. C. Moore The English Historical Review, Volume XVIII, Issue LXX, 1 April 1903, Pages 321–326 https://zenodo.org/record/1855928#.XkLPM0BFyUk
It is very much interesting to compare this account - along with the earlier one he published in Carnet de la Sabretache - in this one you can clearly see the influence of other sources whereas he is far more down to earth in his Sabretache one.