Classification
GHM - Sedimentary rocks
6
GHHM - Diagenesis
4
GBA - General geology, historical geology
2
GBAK - Paleontology
2
GBHB - Geology of continental shelves
2
GHHF - Sedimentary basins
2
EFE - Petroleum geology
1
EFN - Petroleum exploration, natural gas exploration
1
GBH - Marine geology
1
GBHC - Ocean floor - sediments, morphology
1
GCAC - Regional geology - noneuropean countries
1
GFA - Mineralogy - general
1
GFAC - Specific minerals
1
GHMB - Sandstone, conglomerate
1
GMK - Geochemistry of elements, minerals, rocks
1
GVA - Oceanography
1
LBLC - Paleontology - biological aspects
1