@Article{npg-10-589-2003,
AUTHOR = {Boudjema, M. and Santos, I. B. and McCall, K. R. and Guyer, R. A. and Boitnott, G. N.},
TITLE = {Linear and nonlinear modulus surfaces in stress space, from stress-strain measurements on Berea sandstone},
JOURNAL = {Nonlinear Processes  in Geophysics},
VOLUME = {10},
YEAR = {2003},
NUMBER = {6},
PAGES = {589--597},
URL = {http://www.nonlin-processes-geophys.net/10/589/2003/},
DOI = {10.5194/npg-10-589-2003}
}