Any good book recommendations for adults?

Hi all!

After some personal research and years of experience with a person quite close to me, namely my brother, I have a feeling he might be on the autism spectrum.

This might sound condensending towards him, but I mean the best for him. Seeing him living his life not to his fullest is kind of hard for me to see. He's quite stubborn and has a closed personality which doesn't allow me to ask him directly.

What I'm looking for is a book that explains the spectrum, give some insights and personal anecdotes, just to show what's what. I'll read it first and see if I can still stand by my believes. And if I do, I'll try to let him read it to nudge him in the right direction.

Thanks in advance!