A descent method with relaxation type step. - Ulf Brännlund (System Modelling and Optimization, 1993)

A generalized subgradient method with relaxation step. - Ulf Brännlund (Math. Program., 1995)

A descent proximal level bundle method for convex nondifferentiable optimization. - Ulf Brännlund; Krzysztof C. Kiwiel; Per Olov Lindberg (Oper. Res. Lett., 1995)

Railway Timetabling Using Lagrangian Relaxation. - Ulf Brännlund; Per Olov Lindberg; Andreas Nõu; Jan-Eric Nilsson (Transp. Sci., 1998)

Nondifferentiable Optimization: Relaxation Methods. - Ulf Brännlund (Encyclopedia of Optimization, 2009)

Nondifferentiable Optimization: Subgradient Optimization Methods. - Ulf Brännlund (Encyclopedia of Optimization, 2009)