{"version":"1.0","type":"rich","provider_name":"EbookNetworking","provider_url":"https://www.ebooknetworking.net","title":"Methods & Results.: Secular Variation of the Magnetic Declination in the United States & at Some Foreign Stations.","author_name":"Author Unknown","thumbnail_url":"https://www.ebooknetworking.net/books/B00/2JT/bigB002JTX3IG.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-B002JTX3IG.html\">Methods &amp; Results.: Secular Variation of the Magnetic Declination in the United States &amp; at Some Foreign Stations.</a>","width":400,"height":300}