Extracting the CP-conserving and CP-violating form factors of KL → γγ, KS → γγ, and π0 → γγ from the decays of KL, KS and π0 into two identical pairs of leptonsZ.E.S. UyEur. Phys. J. C, 23 1 (2002) 113-120DOI: https://doi.org/10.1007/s100520100853