TY - BOOK AU - Leonard, Joseph W PB - Coal Research Bureau, West Virginia University TI - Research needs in coal mining / Joseph W. Leonard T3 - Technical report (West Virginia University. Coal Research Bureau) ; no. l00. KW - Coal mines and mining -- Research. CY - Morgantown, W. Va PY - 1973 M1 - Accessed from https://nla.gov.au/nla.cat-vn4551239 ER -