{"version":"1.0","type":"rich","provider_name":"EbookNetworking","provider_url":"https://www.ebooknetworking.net","title":"A Method for calculating mine ventilation pressure losses using computers and desk-top calculators: a supplement to Information circular 7809","author_name":"Unknown","thumbnail_url":"https://www.ebooknetworking.net/books/B00/40Z/bigB0040ZOX1I.jpg","thumbnail_width":330,"thumbnail_height":500,"html":"<a href=\"https://www.ebooknetworking.net/books_detail-B0040ZOX1I.html\">A Method for calculating mine ventilation pressure losses using computers and desk-top calculators: a supplement to Information circular 7809</a>","width":400,"height":300}