http://www.bliley.net/XTAL/Industry-Hams.htmlTHE INFLUENCE OF AMATEUR RADIO ON THE DEVELOPMENT OF THE COMMERCIAL MARKET FOR QUARTZ PIEZOELECTRIC RESONATORS IN THE UNITED STATES. By Patrick R. J. Brown, Hewlett Packard Company, Spokane Division
"Wireless Club at Columbia" The Sun. November 25, 1908. Page 2. New York, NY. - Obtained from Library of Congress Chronicling America project. The article is visible directly below the conspicuous ad for "Hanan Shoes".
“Archived copy”. 2012年1月19日時点のオリジナルよりアーカイブ。2014年1月7日閲覧。 Role of Amateur Radio in Development Communication of Bangladesh. Information & Communication Technology for Development. By Bazlur Rahman
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“Archived copy”. 2012年1月19日時点のオリジナルよりアーカイブ。2014年1月7日閲覧。 Role of Amateur Radio in Development Communication of Bangladesh. Information & Communication Technology for Development. By Bazlur Rahman