Blender 3D tip — Realistic Specular value in Principled shader - BlenderNation
How to Use Blender's new ULTIMATE Shader: Principled — Blender Guru
How to Use Blender's new ULTIMATE Shader: Principled — Blender Guru
Trying the Principled BSDF shader in Blender 3D | The Principled shader in Blender 2.79 works partially real time, allowing to edit some material features on the fly and use OpenGL rendering