@misc{indiciae6c6b75be1980,
  title = {Covariant method for calculating helicity amplitudes.},
  author = {R Vega and J Wudka},
  year = {1996},
  doi = {10.1103/physrevd.53.5286},
  url = {https://pubmed.ncbi.nlm.nih.gov/10020525/},
  note = {Source identifier: 10020525}
}