00643nam a2200181ua 4500003001000000005001700010008004100027040003000068110005300098245002400151260006300175500004500238500002400283650002300307655001700330999001700347952009700364AR-SsjUCA20250715141521.0250228s1973 xxk 000 0 eng d aAR-SsjUCAbspacAR-SsjUCA2 aNational Coal Board (Gran Bretaña) NCB 93064510aSurveying practice. aLondon :bNational Coal Board :bMining Department,c1973. aCab. Port. NCB (Mining) codes and rules. aIncluye 28 figuras. 4aTopografía93334 4aTexto924088 c18727d18727 00104070aCAbCAd2014-10-11l0o528 SUR Ej.1pCA3724r2025-07-15 00:00:00w2025-07-15yLB