Valve Hammer Editor Beta 3.5 file - Half-Life - Mod DB
How to Optimize a Map in Hammer Editor: 10 Steps (with Pictures)
Hammer Editor – Simple room example | Jack Goodall
Valve Hammer Editor - Prefabs - YouTube
I was using the hammer editor and noticed that ragdolls eyes stare at you all the time and its so creepy i kinda wanna stop messing with this map for now :
Valve Hammer Editor - Official TF2 Wiki | Official Team Fortress Wiki
How to Optimize a Map in Hammer Editor: 10 Steps (with Pictures)