000 Computer Science, knowledgy & systems
004 data processing & computer science
620 Engineering & allied operations
621.3 Electrical, magnetic, optical, communications, computer engineering;electronics, lighting
621.31 Generation, modification, storage, transmission of electric power
621.319 Electric transmission and distribution
621.32 Lighting
621.33 Electric power transmission for railroads
621.34 Magnetic engineering
621.35 Superconductivity
621.36 Optical engineering
621.37 Testing and measurement of electrical quantities
621.38 Electronic, communications engineering
621.39 Computer engineering