8 Tips for Clean Topology in Blender (Updated for 2021) - CG Cookie | Learn Blender, Online Tutorials and Feedback
Holes for mesh surfaces - User Feedback - Blender Developer Talk
modeling - How to fill multiple holes? - Blender Stack Exchange
Why Does The Boolean Modifier Not Fill In The Holes? – blender base camp
Blender 2.8 Three Ways of Filling Different Types of Holes | Hello everyone! This is a beginner's tutorial showing you different ways to close 3D model mesh holes using the new Blender