TY  - JOUR 
T1  - A variational formulation to image inclusions in 2D travel time cross hole tomography
JO  - Revista Brasileira de Geofísica
A1  - Imhof, Armando Luis
A1  - Calvo, Carlos Adolfo
SN  - 0102-261X
UL  - 10.1590/S0102-261X2003000300006
VL  - 21 
Y1  - 2003
PB  - Brasil 
ER  -