Read it Up Side Down
If you have doubts about how trout see natural surface food from underneath, this is the book to read. It gives you comprehensive and accurate background and investigations about trout feeding behavior.
Both authors are well known and you can follow their thorough and exciting work to accomplish a fly which is considered the ultimate to fool trout.
And to do this the fly is tied Up-side-down.
Read it and be thrilled about background story and a lot of detailed facts about trout and its feeding behaviour.
You will not get dissapointed !