{"version":"1.0","type":"rich","provider_name":"EbookNetworking","provider_url":"https://www.ebooknetworking.net","title":"Specification for an acoustic coupler (IEC reference type) for calibration of earphones used in audiometry: [metric units] (BS4668. 1971)","author_name":"British Standards Institution","thumbnail_url":"https://www.ebooknetworking.net/books/noimage.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-0580062570.html\">Specification for an acoustic coupler (IEC reference type) for calibration of earphones used in audiometry: [metric units] (BS4668. 1971)</a>","width":400,"height":300}