TY  - JOUR 
T1  - Sewing string tree vertices with ghosts
JO  - Brazilian Journal of Physics
A1  - Sandoval Junior, Leonidas
SN  - 0103-9733
UL  - 10.1590/S0103-97332002000100035
VL  - 32 
Y1  - 2002
PB  - Brasil 
ER  -