著者名,論文名,雑誌名,ISSN,出版者名,出版日付,巻,号,ページ,URL,URL(DOI) VALENTA V.,"Survey on spectrum utilization in Europe : Measurements, analyses and observations","Proc. CrownCom2010, June",,,2010,,,,https://cir.nii.ac.jp/crid/1573668924814647424,