The book titled "Regional Frequency Analysis: An Approach Based on L-Moments" is the current authority on using L-Moments in any type of frequency analysis. Every step of the process is described in detail and examples are given along the way to make the method clear. The code that was developed into the current version of Hydro-FIT was inspired by and mimics the steps described in this book. Obtaining and reading a copy of "Regional Frequency Analysis" is highly recommended. This book can be purchased on Amazon. The description on Amazon is as follows:
"Extreme environmental events, such as floods, droughts, rainstorms, and high winds, have severe consequences for human society. Regional frequency analysis helps to solve the problem of estimating the frequency of these rare events at one site by using data from several sites. This book is the first complete account of the L-moment approach to regional frequency analysis. Regional Frequency Analysis comprehensively describes the theoretical background to the subject, is rich in practical advice for users, and contains detailed examples that illustrate the approach. This book will be of great value to hydrologists, atmospheric scientists and civil engineers, concerned with environmental extremes."