Discover and read the best of Twitter Threads about #mathselfpublishign
Most recents (1)
Here is an interesting conversation from Reddit regarding, "an affordable self publishing resource:" reddit.com/r/selfpublish/… 
#mathselfpublishing - of course this is from about 5 years ago, but a full answer. "Ingram Spark" @IngramSpark is recommended, but it sounds like they have strict input file requirements!
Looks like you can do both print and an Ebook for $49 per title as a base price on Ingram Spark.
