Classification
GBHC - Ocean floor - sediments, morphology
2
GVA - Oceanography
2
GBA - General geology, historical geology
1
GBAH - Stratigraphy, history of earth
1
GBAK - Paleontology
1
GBH - Marine geology
1
GCAA - Regional geology - Germany
1
GDA - Engineering geology - general
1
GKKA - Geophysical well logging
1