Classification
GBA - General geology, historical geology
2
GBAH - Stratigraphy, history of earth
2
GCAC - Regional geology - noneuropean countries
2
GAN - Geosciences - mathematical methods, computer applications
1
GBAK - Paleontology
1
GBE - Geology - endogene processes, exogene processes
1
GBEA - Geochronology
1
GCA - Regional geology
1
GCAA - Regional geology - Germany
1
GHH - Sedimentary petrography - general
1
GMP - Geochemical exploration
1
GUAA - Geography - physical
1