TY  - RPRT
TI  - On the two-photon-exchange contribution to pi 0-->e+e- gamma.
AU  - G Tupper
PY  - 1987
DO  - 10.1103/physrevd.35.1726
UR  - https://pubmed.ncbi.nlm.nih.gov/9957844/
ID  - 9957844
ER  -