Author,Title,Edition,Publisher,Year,Series,Number,ISBN,ISSN,URL
"United States International Trade Commission and Baker, Scott","Microphones, loudspeakes [i.e. loudspeakers], and electric sound and visual signaling apparatus",,U.S. International Trade Commission,1984,USITC publication,,,,https://cir.nii.ac.jp/crid/1130282271263330304