Hi Postgres fans, I would like to obtain a printed copy of the PostgreSQL manual. It appears that the manual is available on Amazon at the link below, split into six volumes. https://www.amazon.com/dp/B0CQTMLZ5Y?binding=paperback My question is: Are these copies legit and actually made available by the PostgreSQL project? It appears so, but I'd like ensure my purchase goes toward supporting the project in some small way. Also, is anyone aware whether these printed manuals are available from any other booksellers online? Thanks, - Ben