E13: Carboniferous and Coal in the Ruhr Valley
2010 ◽
Vol 66
◽
pp. 226-236
Keyword(s):
2019 ◽
Vol 94
◽
pp. 47-53
Keyword(s):
1981 ◽
Vol 1981
(4)
◽
pp. 225-235
Keyword(s):