Note that this option will not find the titles of articles in the journals. There are indexes in U-Search for that function. Subject headings are based on the Library of Congress subject headings system, a programmed vocabulary. Subjects are best used if you need information about a person rather than by that person. Every book has an international standard book number.
Every journal has an international standard serial number.
Some composers such as Mozart or Bach have numbering systems applied to their works. If you know the numbers, you can find the specific book, journal or musical piece using this option. Note that one misplaced digit will mean that you will not find the work. Every piece of material in the library has a unique call number. The call number is the address of the book.