Bureau of Mines / Minerals yearbook: Area reports: international 1971
Year 1971, Volume 3 (1971)
Cservenyak, Frank J.
Netherlands, pp. 591-603 ff. PDF (1.3 MB)
http://rightsstatements.org/vocab/NoC-US/1.0/| As a work of the United States government, this material is in the public domain.| For information on re-use see: http://digital.library.wisc.edu/1711.dl/Copyright