There is no good lighting that is healthy and for our well being without proper darkness.
~ Roger van der Heide
Buy awesome books published by Roger van der Heide :
Indian Users : Amazon IN | Flipkart
International Users : Amazon COM
USA Users : Amazon | Canada Users : Amazon CA
UK Users : Amazon UK | German Users : Amazon DE
French Users : Amazon FR | Italy Users : Amazon IT
Brazil Users : Amazon BR | Mexico Users : Amazon MX
Spain Users : Amazon ES |China Users : Amazon CN
Japan Users : Amazon JP | Australia Users : Amazon AU
