@article{article169613a2,
title   = {A study of penalty formulations used in the numerical approximation of a radially symmetric elasticity problem},
author = {Aguiar, Adair Roberto and Fosdick, Roger L and García Sánchez, Jesus Antonio},
year = {2008},
doi = {10.2140/jomms.},
journal   = {Journal of Mechanics of Materials and Structures}
}