Point of No Return - The Doom Wiki at

Point of No Return is a single-level PWAD for Doom II, created by Michael Philleo (Job) for the ZDoom source port. It is a large techbase map, and represents an early attempt at emulating the style of Playstation Doom through the use of sounds from that version of the game but also the colored sector features from the ZDoom engine used to simulate similar environments. It uses a music track entitled "downlord" by Ubik (aka RocketMermaid).

E1M1: Hangar (Doom), Doom Wiki

Doom novels - The Doom Wiki at

MAP03: The Gantlet (Doom II), Doom Wiki

Doomguy - Wikipedia

Doom (franchise) - Wikipedia

Doom 3 novels - The Doom Wiki at

A.L.T. - The Doom Wiki at

Thy Flesh Consumed - The Doom Wiki at

Doctor Doom - Wikipedia

Siphon Grenade, Doom Wiki