@article{oai:repository.dl.itc.u-tokyo.ac.jp:00033789, author = {Tanaka, Teiji}, issue = {2}, journal = {東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo}, month = {Nov}, note = {application/pdf}, pages = {325--332}, title = {An Instrument for Brief Measurement of the Natural Period of a Building}, volume = {40}, year = {1962} }