@article{01184306,
title = {Wave equations with low regularity coefficients.},
journal = {Documenta Mathematica},
year = {1998},
pages = {723-730},
zbl = {0909.35081},
language = {en},
url = {http://dml.mathdoc.fr/item/01184306}
}
Smith, Hart F. Wave equations with low regularity coefficients.. Documenta Mathematica, (1998), pp. 723-730. http://gdmltest.u-ga.fr/item/01184306/