Looking for more online primary sources? See our full online primary sources guide
Library books are arranged by the Dewey Decimal classification scheme whereby each subject is represented by a number. You will find books on the same subject will have the same number. The shelfmark is preceded by the letter D and will be followed by 3 letters, which are usually the first 3 letters of the author's name.
Useful History and related subjects shelfmarks:
D 610.9 History of medicine
D 940 European history
D 941.1 Scottish history
D 941.5 Irish history
D 947 Russian history
D 956 Middle Eastern history
D 973 American history