File:Symbol Induktor (with Air gap in the Core).svg - Wikimedia Commons
Air gap [Encyclopedia of electromagnetics]
Gyrator–capacitor model - Wikipedia
Air gap [Encyclopedia of electromagnetics]
File:High voltage testing arrangement with air gap sphere.jpg - Wikimedia Commons
Focus On: 100 Most Popular 1990s Fashion: Adidas, Nike, Inc., Air Jordan, Gucci, Dreadlocks, Tattoo, Reebok, Levi Strauss & Co., Puma (brand), Gap Inc., etc. - Kindle edition by Wikipedia contributors. Reference