Stalker: Call of Pripyat → Quests → Mercenary Camp
Sych asks you to visit the mercenary camp and search for any information there. Preferably, the mercenaries' plans. They're well-armed, so it's worth approaching this matter seriously, armed with something like a sniper rifle, like the Priboi. Once the entire mercenary "population" of the base has departed for the afterlife, it's time to search for information.
For starters, you can loot Khrebet's PDA from his body. He'll probably pay for it. A short search will also reveal a laptop with the plans. Everything that can be found has been found. Now I need to show it to Sych. He'll buy the PDA for 1,000 rubles, and the laptop for 2,000.
Source: gamer.ru
See also:
Fishing in Terraria
Fallout Tactics: Ammo
Polysaccharides. Chemistry