My random translations of the photo captions, clockwise from top left are:

• Lark W
• Shimano 100 mini
• Lark SS
• Lark W

• Publisher: New Cycling
• Document: New Cycling May 1981 - '81 Derailleur Collection
• Date: May 1981
• Derailleur brands: Shimano
• Derailleurs: Shimano Lark SS, Shimano Lark-W, Shimano Lark-W (D280), Shimano 100