Universal Decimal Classification

  1. Gabon. Gabonese Republic. République Gabonaise
  2. Gallegan (Galician)
  3. Gallo-Romance / Gallo-Romanic languages
  4. Gallo-Romance languages
  5. Game theory
  6. Games involving forfeits
  7. Games not characterized by action
  8. Games of motion and skill with special equipment
  9. Games of pure chance
  10. Garden plants. Gardening
  11. Ge-Pano-Carib languages
  12. Ge-Pano-Carib languages. Macro-Chibchan languages
  13. Gender studies
  14. Genealogy
  15. General and professional pharmacy
  16. General and theoretical biology
  17. General botany
  18. General characteristics of machines etc.
  19. General concepts and laws
  20. General ecology and biodiversity
  21. General genetics. General cytogenetics
  22. General geography. Science of geographical factors (systematic geography). Theoretical geography
  23. General geology
  24. General geology. Meteorology. Climatology. Historical geology. Stratigraphy. Palaeogeography
  25. General history
  26. General laws of phenomena
  27. General laws. Theoretical aspects. Characteristics. Properties
  28. General libraries
  29. General linguistics
  30. General mechanics. Mechanics of solid and rigid bodies
  31. General metaphysics. Ontology
  32. General microbiology
  33. General networking applications and services
  34. General operations and activities
  35. General organization of statistics. Official statistics
  36. General organization of the armed forces
  37. General principles and theory of measurement and the design of measuring apparatus. Measurement methods
  38. General problems of mathematical logic. Foundations of mathematics
  39. General processes
  40. General questions of breeding and rearing
  41. General questions of composition and interpretation
  42. General questions of didactics and method
  43. General questions of trade and commerce. Market
  44. General questions relating to both linguistics and literature. Philology
  45. General questions. Geography as a science. Exploration. Travel
  46. General reference works (as subject)
  47. General staff: personnel, organization
  48. General structure of the Earth
  49. General stylistics
  50. General theory of heat
  51. General theory of music
  52. General theory of signs in relation to linguistics. Semiology. Semiotics
  53. General toxicology. General studies of poisons and poisoning (intoxication)
  54. General zoology
  55. Generalities of civil law
  56. Generalities on oils, fats, waxes and products derived from them
  57. Genre, subject, style of film
  58. Geoastronomy. Cosmogony
  59. Geobiology. Geological actions of organisms
  60. Geochemistry
  61. Geochronology. Geological dating. Determination of absolute geological age
  62. Geodesy. Surveying. Photogrammetry. Remote sensing. Cartography
  63. Geodetic instruments and equipment
  64. Geodetic surveying
  65. Geographic botany. Plant geography (phytogeography). Floras. Geographic distribution of plants
  66. Geographic zoology. Zoogeography. Fauna. Geographic distribution of animals
  68. Geography. Exploration of the Earth and of individual countries. Travel. Regional geography
  69. Geological (lithological / biological / palaeoecological) time division
  70. Geological, archaeological and cultural time divisions
  71. Geometry
  72. Geomorphology. Study of the Earth's physical forms
  73. Geophysics
  74. Georgia. Republic of Georgia. Sakartvelo. Sakartvelos Respublika
  75. Georgian
  76. Georgian language
  77. Georgian literature
  78. Geotectonics
  79. German
  80. German language (High German, Standard written German)
  81. German literature
  82. Germanic languages
  83. Germanic languages
  84. Germany. Federal Republic of Germany. Bundesrepublik Deutschland
  85. Ghana. Republic of Ghana
  86. Glaciology
  87. Glandular system. Secretion. Excretion
  88. Glass industry. Ceramics. Cement and concrete
  89. Glass industry. Glass technology. Glass manufacture in general. Glass in the comprehensive sense
  90. Glazed earthenware
  91. Gloving. Glovemaking
  92. Glyptics. Sigillography
  93. God. Gods (Personalised god(s) as distinct from immanent spirits)
  94. Goidelic group
  95. Gold and silver articles. Articles of other precious metals. Jewellery
  96. Goldsmith's and silversmith's art
  97. Government of the religion
  98. Governmental organizations and cooperation
  99. Grammar
  100. Graphemics. Orthography. Spelling
  101. Graphic art, printmaking. Graphics
  102. Graphic expression of language
  103. Graphic industries. Printing. Publishing. Book trade
  104. Graphic reproduction machines and equipment
  105. Gravity. Gravitation. Pendulums. Ballistics
  106. Greece. Hellenic Republic. Elliniki Dimokratia
  107. Greek (Hellenic)
  108. Greek (Hellenic) language
  109. Greek (Hellenic) literature
  110. Greenland/Gronland (Denmark)
  111. Groundwater hydrology. Geohydrology. Hydrogeology
  112. Guarani languages
  113. Guatemala. Republic of Guatemala. República de Guatemala
  114. Guidance, control-initiation and navigation systems and instruments (vehicle-borne)
  115. Guidebooks (with practical and descriptive information)
  116. Guinea-Bissau. Republic of Guinea-Bissau. República da Guiné-Bissau
  117. Guinea. Republic of Guinea. République de Guinée
  118. Gujarati
  119. Guyana. Co-operative Republic of Guyana
  120. Gymnastics. Acrobatics. Athletics
  121. Gymnophiona
  122. Gymnospermopsida. Plants with naked seeds
  123. Gynaecology. Obstetrics
  124. Gypsum, lime and cement industries. Hard-setting materials. Plasters and compositions. Mortar and concrete