Book Depository allows this in its Advanced Search box. https://www.bookdepository.com/search/advanced https://www.bookdepository.com/search/advanced Enter "I

Book Depository allows this in its Advanced Search box. https://www.bookdepository.com/search/advanced https://www.bookdepository.com/search/advanced Enter "Independently Published" for publisher, then whatever keyword you want. Using "network" turns up a really good one I'm currently working through: "Beej's Guide to Network Programming: Using Internet Sockets"