This excerpt is from How To Sell Stocks Short by William J. O'Neill. He's describing his famous "follow-through day" tp confirm reversals. It's a short and sweet read with tons of chart examples. smile.amazon.com/Make-Money-Selling-Stocks-Short/dp/0471710490/
The "volume-drop-off = reversal" phenomenon might not be explicitly stated in the book, but is self-evident and demonstrated in the ideas below.