LEADER 00000nam 2200229 a 4500 001 0065567 003 UkHlHU 007 t 008 002807 0 1928 000 eng 040 UkHlHU 050 4 HD 9540 D7 100 0 Dron, Robert Wilson. 245 04 The economics of coal mining. 260 London :|bE. Arnold,|c1928. 300 168p. 946 6XX absent
