This Old House Landscape Contractor Jenn Nawada offers some advice on how to adjust sunken sprinkler heads.
Installing Your Own Sprinkler System - Pretty Handy Girl
How To Replace or Raise a Sprinkler Head - This Old House
Retrofitting Fire Sprinklers: What a Big Project Needs for Success
The Dos and Don'ts of Sprinkler Repair and Maintenance - Bob Vila
How to Find Buried Sprinkler Heads — Commercial Lawn Irrigation
HELP! My Sprinkler Head is Busted! What will it cost to repair? {And
Sprinkler System Ideas for a Beautiful Lawn
Is there a better way to raise sprinkler heads than this terrible plastic riser that is prone to breaking? : r/lawncare
Why Leaks in Your Sprinkler System are More Expensive Than You Might Think - Smart Earth Sprinklers
How to Winterize Your Sprinkler System - The Home Depot
Rain Bird Rotor Heads 5000 Rotor Sprinkler Heads. 4-Pack : Patio, Lawn & Garden
Above Ground Irrigation Systems for Landscaping