What if a patron wants to find books on a certain subject?

Library of Congress Classification System: G


G     Geography, Anthropology, Recreation (Lower Level)

G: Geography (General), Atlases

GA: Mathematical geography, Cartography

GB: Physical geography

GC: Oceanography

GE: Environmental sciences

GF: Human ecology, Anthropogeography

GN: Anthropology

GR: Folklore

GT: Manners and customs (General)

GV: Recreation, Leisure