Are Piper Vortex Generators Worth It? The consensus seems to be

Piper Warrior - Aviation Consumer

Electroair Electronic Ignition: Modernizing my Arrow's starter

Restoring a Piper Interior (Comanche Restoration Series Part 3

Efficiency: Stuck on vortex generators - AOPA

Electroair Electronic Ignition: Modernizing my Arrow's starter

Spiff Up Your Piper for $12

Are Cessna Vortex Generators Worth It? The consensus seems to be

TASC Consensus paper - Perimed France

Better Than New: Making my own Turbo Arrow V

Various types of vortex generators

Investigation on the influence of vortex generator on particle

Piper Vortex Generators VGs Review — Piper Forum

Issue 16 - Practical Guide to Free-Energy Devices