{"version":"1.0","type":"rich","provider_name":"EbookNetworking","provider_url":"https://www.ebooknetworking.net","title":"Introduction to the Calculus of Variations","author_name":"William Elwood Byerly","thumbnail_url":"https://www.ebooknetworking.net/books/114/153/big1141537249.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-1141537249.html\">Introduction to the Calculus of Variations</a>","width":400,"height":300}