Rhif Galw
000 - Computer science, information, general works
55
100 - Philosophy & psychology
41
200 - Religion
29
300 - Social sciences
419
400 - Language
59
500 - Natural sciences and mathematics
53
600 - Technology (Applied sciences)
179
700 - The arts
71
800 - Literature (Belles-lettres) and rhetoric
111
900 - History & geography
104