BookBub (Requires email sign up. Be sure to use a personal non-work email.)
Google Play: Top Free in Books (Have to be signed in to your Gmail)
InTech (Open Access books and journals covering science, technology, and medicine)
The National Academies Press (Free to read online. Has a section on "Conflict and Security Issues")
Open Book Publishers (Free to read online)
Oyster (Not free, but $9.95 a month all you can read)
Project Gutenberg: Free eBooks (You may not be able to access this site on government computers)
This guide contains a mix of sources; some can be read online or streamed, others can be downloaded to devices.
Apps and software cannot be downloaded onto government computers. Any of the resources included in this guide which require downloading an app or additional software (e.g., iTunes) should be accessed on a personal computer or device.
Any accounts or email sign ups should be created using a personal email not your government email.