cycles render engine - Making a HDRI map more subtle creates a drop shadow - Blender Stack Exchange
Better HDR-Lighting and how to get great shadows - for 3ds-Max, Blender, Modo, and most other 3d. - YouTube
Blender – Adding a texture to an Area Light – Oded Maoz Erell's CG Log
Cycles] Ground for HDRi Environment (aka Shadow / Light Catcher) - Blender Tests - Blender Artists Community
HDRI light setup vs just a color gives very different behaviour in how shadows are showing up :( how do I get them soft and diffused with HDRI? : r/blender
Blender 3D - How to control Soft Shadows - YouTube