@inproceedings{CTT100598109,
  author = {Y. Niwa and S. Hirose},
  title = {Theoretical analysis of seismic waves in a dipping layer},
  booktitle = {Proc. Japan Soc. Civil Eng.},
  year = 1983,
}

@inproceedings{CTT100598119,
  author = {Y. Niwa and M. Kitahara and S. Hirose},
  title = {Elastodynamic problems for inhomogeneous bodies},
  booktitle = {Boundary Elements},
  year = 1983,
}