Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Aida T,Determination of the workability of a coal face underground by measuring the friability of coal,"Memoirs of the Faculty of Engineering, Kyoto University",00236063,Kyoto : Faculty of Engineering,1960-10,22,4,????,https://cir.nii.ac.jp/crid/1520853832656426240,