@article{articlea694692a,
title   = {Nonlinear normal modes of planar frames discretised by the finite element method},
author = {Soares, Mário Eduardo Senatore and Mazzilli, Carlos Eduardo Nigro},
year = {2000},
doi = {10.1016/s0045-7949(99)00233-3},
journal   = {Computers & Structures}
}