Since I learned bridge 11 years before being born I'd like to know which books, resources, etc teach this 1x-1♥-3♥ as 18-19 balanced. It's just to get in touch with modern bridge and to find out what they do with 15-17 unbalanced and 4-card support for hearts. I had seen LOL's bidding 2NT with 4-card support and 18-19 and thought it was some sort of aberration from them or from their teachers. What's the rest of the structure?