I don't think there are any good books on ghosts. Not because I don't believe in their possibility, but because I don't think we really understand what we are perhaps perceiving when we take for granted what we are "sensing" - if indeed they do exist.
Ironically enough, understanding what they are has much to do with time does it not? ^^
Even if it did not / there are possibilities to that (as hard to comprehend as they may be) that could start to rule out some of the "other" possibilities.
Here's one or two off the wall random thoughts for you;
How do you know for 100% certainty that a ghost is not a projection of your mind, or a collective projection of minds in a vicinity?
Perhaps where they occur, there is some quantum never understood particle, that creates a small opposite blackhole effect and imprints time upon time in a layered transparent effect and is being viewed by us both via string theory? (both relating to the mirrored).
I'm not saying they are, I'm only asking you for 100% proof they are not
Then you can get really complex with your imagination and combine the two ideas.
A quantum particle that reacts to conscious thought....
Oh goodness that might just be that double slit thingy...oops - probably shouldn't draw any connotations to ghosts here...
That's the great thing about life, all the possibility ^^ :oops: