@article{01334333,
title = {Geometric proofs of composition theorems for generalized Fourier integral operators.},
journal = {Portugaliae Mathematica. Nova S\'erie},
volume = {56},
year = {1999},
pages = {129-154},
zbl = {0939.35203},
language = {en},
url = {http://dml.mathdoc.fr/item/01334333}
}
Joshi, M.S. Geometric proofs of composition theorems for generalized Fourier integral operators.. Portugaliae Mathematica. Nova Série, Tome 56 (1999) pp. 129-154. http://gdmltest.u-ga.fr/item/01334333/