During the “Old World Blues” expansion, you’ll find various holotapes that are recipes for skill books. You can use these recipes to create said skill books at a Workbench. What this boils down to is you can create one of each type of skill book (only one since the recipe holotapes are ingredients in these recipes themselves). The locations of the recipe holotapes are listed below. You will need Blank Books and Wonderglue to create each book… twenty-five Blank Books, in fact, so collect books to process via the Book Chute in the Sink.

Barter Skill Book

In the Signal Hills Transmitter building, under the metal shelves near the door.

Energy Weapons Skill Book

In the Z-38 Lightwave Dynamics Research building, on top of the catwalk in the north-eastern corner of the level. The book is under a large monitor, just south-east of the upper-level door to the Big MT.

Explosives Skill Book

You’ll find this recipe in the X-7a “Left Field” Artillery Launch, in the Artillery Command Center. The recipe is on the shelf of a large machine, on the northern side of the room.

Guns Skill Book

This one is a bit tricky… fire the artillery guns at the X-7a “Left Field” Artillery Launch area, which will create a crater at the X-7b “Boom Town” Target Zone. Fast travel to said location and from where you appear head east, over a ruined car, and into the ruins of a white house. To the north is a metal ramp running over the fence, go up it, and into the crater below. Inside is a footlocker, which contains this recipe.

Lockpick Skill Book

Head into the X-13 Testing Facility - X-13 Stealth Testing Labs area. Head across the bridge to the east and once across, go through the northern door (the door has a terminal on the wall near it and may be locked [Hard] if this is your first time here.) Enter a hallway with a glowing floor and enter the first room to the north, with the “Reception Observation Area” sign near it. In this room, head across another metal bridge to the west until you reach a wall-terminal with a security camera over it. Along the wall to the south is a vent. Jump onto the ledge along the western wall, hugging the wall as you go. There’s a ‘ledge’ that can be navigated. Carefully walk south from the bridge to the vent and open the vent to find this recipe.

Medicine Skill Book

Find this recipe in Higgs Village, house #103. The recipe is upstairs, in the bedroom, on a shelf on a desk.

Melee Weapons Skill Book

You can find this recipe on the roof of the Y-0 Research Center. Jump up on the trucks near the building, then onto the roof. The disk is near the cliff face, by a duffle bag.

Repair Skill Book

In Higgs Village - house #00. Go upstairs and head into the room adjoining the three rooms to the north-west. Along the south-western end of this room you’ll find a terminal on the wall. Go to the terminal, crouch, and turn to face the doorway to the north-west. You should see the recipe sitting between some of the electronics before the doorway.

Science Skill Book

This recipe is in Higgs Village, in house #102, upstairs in the bedroom, in the northern corner of the room on some electronics.

Sneak Skill Book

In the X-13 Stealth Testing Lab, on the lower floor, in the room in the south-eastern corner of the level. The book is on the ground between two refrigerators.

Speech Skill Book

You’ll find this recipe in Higgs Village, house #104. It’s upstairs, in a room full of Teddy Bears and broken mirrors, on top of a radio.

Survival Skill Book

In Little Yangtze. When you enter via the eastern gate, in the first tent to the north. This recipe is under a bed.

Unarmed Skill Book

In the Big MT West Tunnel, in a locked [Easy] room north-west of the entrance.