FAA's Helicopter Flying Handbook - you can read it yourself. But it's what I was taught when I was learning to fly in the 1970's. To recap: The FAA says that SWP *is* VRS.
Your FAA "Bible" has a lot of Fake News in it, being designed to teach the lowest common denominator, so it glosses over things and simplifies them to the point of error.
For example, it states as a fact that the air pressure increases under a rotor disk in IGE, causing less induced flow. Wrong.
On page 2.19 it shows a diagram from above with coloured part on the right saying that with forward motion, the advancing side gets more lift, and the retreating side gets less lift (IF NOTHING IS DONE ABOUT IT) and this will cause the aircraft to roll left. Garbage.
It preaches gyroscopic precession, which should only be used as a guide to understanding the delays in blade movement and the advance angles built into the swash plate to make up for them, not as the reason the disk behaves like it does.
So don't quote the FAA book as being absolute truth, it is merely a teaching aid, and not a particularly good one at that.