-
817.
Public works contracts
Subjects
Public contractsContracts for work and labor
-
818.
Pumping machinery
Subjects
Hydraulic machinery
-
819.
Purification of factory and trade waste
Subjects
-
820.
Purification of sewage
Subjects
Bacteriology
-
821.
Pyroelectricity
Subjects
CrystallographyElectricity
-
822.
Quarries
Subjects
Economic geology
-
823.
Query languages (Computer science)
Subjects
Programming languages (Electronic computers)
-
824.
Racing automobiles
Subjects
AutomobilesAutomobile racing
-
825.
Rack-railroads
Subjects
Railroads
-
826.
Radar
Subjects
RadioRemote sensing
-
827.
Radio
Subjects
CommunicationsElectric engineeringTelecommunication
-
828.
Radio antennas
Subjects
Antennas (Electronics)
-
829.
Radio circuits
Subjects
Electronic circuits
-
830.
Radio frequency
Subjects
-
831.
Radio frequency identification systems
Subjects
-
832.
Radio in education
Subjects
EducationAudio-visual educationRadio broadcasting
-
833.
Radio in navigation
Subjects
Aids to navigation
-
834.
Radio stations
Subjects
-
835.
Radioactive waste sites
Subjects
Hazardous waste sitesRadioactive waste disposa
-
836.
Radioreceptors
Subjects
-
837.
Rail transport modelling
Subjects
Models and model making
-
838.
Railroad engineering
Subjects
Civil engineering
-
839.
Railroad fares
Subjects
Railroads and state
-
840.
Railroad history
Subjects
Last updated dated: 20/10/2024