@article{article04bef3e2,
title   = {Mixed and penalty finite element models for the nonlinear behavior of biphasic soft tissues in finite deformation: pt.I - alternate formulations},
author = {Almeida Neto, Edgard Sant'Anna de and Spilker, R L},
year = {1997},
journal   = {Computer Methods in Biomechanics and Biomedical Engineering}
}