TY  - RPRT
TI  - Open superstrings in four dimensions.
AU  - Z Bern
AU  - DC Dunbar
PY  - 1990
DO  - 10.1103/physrevlett.64.827
UR  - https://pubmed.ncbi.nlm.nih.gov/10042091/
ID  - 10042091
ER  -