Swing Index (SWING)

Author
J. Welles Wilder

Reference
Book New Concepts in Technical Trading Systems [Amazon.com]
by J. Welles Wilder; Trend Research. ISBN:0894590278

Interpretation / Algorithm
Technical Analysis Studies [prophet.net]
Description with math formula [FMLabs.com]
Technical Analysis A to Z by Steven B. Achelis [equis.com]