NICHIA Introduces High-Power 1800K LED as Industry's Only True Alternative to High Pressure Sodium Lamps — LED professional - LED Lighting Technology, Application Magazine
Sodium-vapor lamp - Wikipedia
Sodium-vapor lamp - Wikipedia
Sodium-vapor lamp - Wikipedia
The Sodium Lamp - How it works and history
Sodium-vapor lamp - Wikipedia
Sodium | Elements | RSC Education
New York's Street Lamps in Flux | The New Yorker
Lamp - Fluorescent, Halogen, LED | Britannica
The Sodium Lamp - How it works and history
A Light at the Smithsonian – SpectroClick
Low Pressure Sodium Lighting - Flagstaff Dark Skies Coalition
Like It or Not, Chicago's About to Get a Lot Less Orange – Chicago Magazine
The Sodium Lamp - How it works and history
Lighting-Gallery.net - Thermal discharge lamps/1997 Sylvania LU750 – The first American high-performance sodium lamp
Sodium-vapor lamp - Wikipedia
RAB LHPS70 High Pressure Sodium Lamp 70W Barn Yard Light 6,500 Lumens Outdoor | eBay
The Sodium Lamp - How it works and history
The Sodium Lamp - How it works and history
History of low-pressure sodium lighting
Thorn First 70W SON-E High Pressure Sodium
History of Street Lighting - Development of Street Lighting Technology
The Low Pressure Sodium Lamp
A Light at the Smithsonian – SpectroClick
Sodium-vapor lamp - Wikipedia
