For most dissertation topics, you will need to make use of other libraries as well as SIA's physical and online resources.
For finding books that SIA does not have, Library Hub Discover is usually best.
Library Hub Discover does not tell you which of the libraries it lists you can access, or how to arrange a visit. For this info, please visit:
This guide also gives details of libraries where the librarians may be able to give you further research advice. Even at libraries which do not offer this service, you may be lucky to find a librarian who has the time and the knowledge to give you a little help with research ideas.
Some libraries offer databases not available at SIA, usually only accessible from the library's own computers.
The SIA librarians are happy to help if you are unsure how to access a particular library, or cannot track down an important book or other resource.