-
769.
Permanent magnets
Subjects
Magnets
-
770.
Personal transporters
Subjects
Vehicles
-
771.
Petroleum chemicals industry
Subjects
Petroleum industry and trade
-
772.
Petroleum engineering
Subjects
Mining engineering
-
773.
Petroleum industry and trade
Subjects
Energy industries
-
774.
Petroleum pipelines
Subjects
Pipe
-
775.
Petroleum prospecting
Subjects
Petroleum engineeringProspecting
-
776.
Petroleum refineries
Subjects
Petroleum refining
-
777.
Pharmaceutical technology
Subjects
-
778.
Phase-locked loops
Subjects
Electric oscillators
-
779.
Philosophy of technology
Subjects
-
780.
Phonograph
Subjects
-
781.
Phonograph records
Subjects
Sound recordings
-
782.
Photoelectric cells
Subjects
-
783.
Photographic equipment
Subjects
-
784.
Photographic industry
Subjects
-
785.
Photorefractive materials
Subjects
-
786.
Photovoltaic cells
Subjects
Photoelectric cells
-
787.
Photovoltaic effect
Subjects
Photoelectricity
-
788.
Photovoltaic power generation
Subjects
Direct energy conversionSolar energyPhotovoltaic effect
-
789.
Photovoltaic power systems
Subjects
Solar power plants
-
790.
Physical instruments
Subjects
Scientific apparatus and instruments
-
791.
Piezoelectricity
Subjects
CrystallographyElectricity
-
792.
Pilot guides
Subjects
NavigationPilotage
Last updated dated: 21/02/2026