@article{sandoval junior_2002, title={Sewing string tree vertices with ghosts}, volume={32}, ISSN={0103-9733}, url={https://doi.org/10.1590/S0103-97332002000100035}, DOI={10.1590/S0103-97332002000100035}, number={1}, journal={Brazilian Journal of Physics}, publisher={Sociedade Brasileira de Física}, author={Sandoval Junior, Leonidas}, year={2002}, month={Mar}, pages={232–254} }