13 Official rules of table tennis serve: General and specific. - INDOORTION
This should be ILLEGAL in table tennis! Behind the back shots : r/ tabletennis
Detection of illegal treatment of table tennis rackets using gas chromatography coupled to ion mobility spectrometry – A feasibility study - ScienceDirect
Can You Throw Your Bat In Table Tennis? - The Racket Life
Is this allowed /legal ??? - Alex Table Tennis - MyTableTennis.NET Forum
Table Tennis: Rules and history to know for the 2021 Olympics