Classification
GVA - Oceanography
51
GBHC - Ocean floor - sediments, morphology
27
GBH - Marine geology
6
GDA - Engineering geology - general
5
GKKA - Geophysical well logging
4
GBAH - Stratigraphy, history of earth
2
GBAK - Paleontology
2
GDAC - Seismicity, earthquake engineering
2
GCAC - Regional geology - noneuropean countries
1