On-shell Recursion Relation for String Tree-level Amplitude

          @misc{ scivideos_PIRSA:12050003,
            doi = {10.48660/12050003},
            url = {https://pirsa.org/12050003},
            author = {Feng, Bo},
            keywords = {Quantum Fields and Strings},
            language = {en},
            title = {On-shell Recursion Relation for String Tree-level Amplitude},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2012},
            month = {may},
            note = {PIRSA:12050003 see, \url{https://scivideos.org/index.php/pirsa/12050003}}
          }