I have just checked and I do see that I have devoted a chapter on the matter in my most wondrous "Wit and Wisdom of Mark Lewis" e-book. It can be obtained at
http://www.marklewisentertainment.com/h ... cians.html
I don't think I was yapping about nervousness on this forum but elsewhere on another forum. That is why your search ended in failure.
Dai Vernon suffered from stagefright so you are not alone. Here is one tip if you are doing close up magic on an impromptu basis. I have not mentioned this in my book. Just admit to your spectators that you are as nervous as hell! By admitting it you will be less nervous and evoke a powerful concept which I have also mentioned in my book and have preached incessantly about it here, there and everywhere.
There is a horrible phenomena that affects every magician. It is known as "defensive resentment". I invented the terminology although God invented the phenomena. I have no energy to explain it all here so you will have to buy my book to find out what I am yapping about. It pertains to the fact that laymen don't like being fooled by magicians and they can show resentment over the matter to varying extents depending on that particular layman.
By admitting you are a bag of nerves will help a lot to get rid of that audience resentment. It could turn out to be a blessing in disguise.