Books on observational strategy?

Examples in poker books usually assume you've already figured out your opponents - e.g. they'll tell you that "opponent X has been playing tight" or that "opponent Y will rarely fold to a bluff". Now, from what I've read here on the forum, I understand most poker players think observational skills come with experience. Yet, I feel the learning curve would be less steep, if I had a healthy dose of advice under my belt. There should be some kind of strategy available to streamline the huge amount of information coming at you when playing poker.

Before Doyle Brunson's Super System, people only had experience to rely on for the whole of poker. With the excellent poker literature being published these days, new players can get up to speed much quicker. But, like I've mentioned, there seems to be a gap that hasn't been bridged yet. Or has it?

Are there any books on observational strategy?

i would assume that allan pease "body language" and "caros book of poker tells" would have to be about observations skills their quality im not quite sure