My novel Greyland: D.U.M.B.s (Deep Underground Military Bases) – Book 1 is in a bundle with 11 other exciting books on the theme of Alien Invasion.
Get a great deal on these books, only $2.99! https://bundlerabbit.com/b/they-came
It’s also available from Kobo, Amazon, Barnes & Noble, and iBooks. (The link above lists all of these locations.)