5/3/1 Boring But Big (BBB) is a popular variation of Jim Wendler's famous 531 method for intermediate lifters to gain size and strength. It focuses on high volume accessories to induce hypertrophy after the main strength sets.
5/3/1 BBB is based on Jim Wendler's original article and is also free on the Reddit r/fitness wiki. Be sure to check out Jim's 5/3/1 Forever book, which collects all of Jim's methods.