@article{articlef3cc200a,
title   = {Optimization of material distribution in functionally graded structures with stress constraints},
author = {Stump, Fernando Viegas and Silva, Emílio Carlos Nelli and Paulino, Gláucio Hermogenes},
year = {2007},
doi = {10.1002/cnm.910},
journal   = {Communications in Numerical Methods in Engineering}
}