I am trying to read the following paper by Leon Brillouin (the part on page 16 onwards): http://www.numdam.org/article/ASENS_1916_3_33__17_0.pdf
Léon Brillouin, Sur une méthode de calcul approchée de certaines intégrales dite méthode du col, Annales scientifiques de l’É.N.S. $3^\text{e}$ série, tome 33 (1916), pp 17–69, doi:10.24033/asens.690.
Is there some English translation to this paper?
I tried using Google translate, but it makes a poor job. Thanks!