%0 Journal Article
%T Why the small-span small-pillar (sssp) concept for underground mining?
%A de Frey
%A F.S.A.
%J Journal of Power and Energy Engineering 电力与能源
%D 2019
%U http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532019000700003&lng=en&nrm=iso&tlng=en