Begin your search in the library catalog for books. You will notice that many of our books on computing are ebooks.
Try using the advanced search tab in the catalog to link the concepts "cloud computing" and "network security" together.
When you find a book in the catalog you really like click on the "show full record" link. scroll down to the subject headings for that title. These headings group like materials together, so you will be able to easily find additional books covering your topic.