by Valdivia, J.A., Rogan, J., Muñoz, V., Gomberoff, L., Klimas, A., Vassiliadis, D., Uritsky, V., Sharma, S., Toledo, B., Wastavino, L.
Published in Advances in space research (2005)

by Wastavino, L.A., Toledo, B.A., Rogan, J., Zarama, R., Muñoz, V., Valdivia, J.A.
Published in Physica A (15.07.2007)