Advances in technology have lowered the cost of entry to publishing your work and many authors have discovered they can "self-publish" their out-of-print titles. Unfortunately, these self-published titles often look self-published, rather than professional. The effort and costs associated with bringing an out-of-print book back to the marketplace can be considerable, including cover art, cover design, interior design, scanning, conversion, proofreading, as well as set-up and distribution fees. And those are just the obviously out-of-pocket costs.
You need a publisher to help you bring those books back into print and make them available for sale directly via the major online booksellers. Please consider Endpapers Press and allow us to reissue your previously published book in eBook and trade-paperback formats.