It doesn't fall under published material per se, but you can find a LOT of good amateur modern sci fi on the alternatehistory.com forums. I feel like it's a site that falls under the radar a fair bit but there's a hell of a lot of content
If that fails, there's always me, lol: Sweet Oblivion: A War of the Worlds Story eBook : Paxton, Samuel: Amazon.co.uk: Kindle Store
By Felix J Palma
1.Map of ion Time
2. Map of the Sky
3. Map of Chaos.
Custer At The Alamo by Gregory Urbach
Kelley Country by A Bertram Chandler
Morlock Night by K W Jeter