@article{oai:repository.dl.itc.u-tokyo.ac.jp:00039647, author = {Terao, Hiroaki}, issue = {2}, journal = {Journal of the Faculty of Science, the University of Tokyo. Sect. 1 A, Mathematics = 東京大学理学部紀要. 第1類A, 数学}, month = {Aug}, note = {application/pdf}, pages = {293--312}, title = {Arrangements of hyperplanes and their freeness I}, volume = {27}, year = {1980} }