Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Moriyasu Takeshita and Motoyuki Sato,Polarimetric borehole radar approach to subsurface fracture classification,SPIE Proceedings,0277-786X,SPIE,2000-04-27,4084,,50-54,https://cir.nii.ac.jp/crid/1874242817866642560,https://doi.org/10.1117/12.383479