@article{GDZPPN002084031,
title = {Commutator Estimates for Pseudodifferential Operators with Negative Definite Functions as Symbols.},
journal = {Forum mathematicum},
volume = {2},
year = {1990},
pages = {155-162},
zbl = {0693.35168},
url = {http://dml.mathdoc.fr/item/GDZPPN002084031}
}
Jacob, Niels. Commutator Estimates for Pseudodifferential Operators with Negative Definite Functions as Symbols.. Forum mathematicum, Tome 2 (1990) pp. 155-162. http://gdmltest.u-ga.fr/item/GDZPPN002084031/