Brandelik, R.(1979). Experimental results on the decay sequences ψ'(3685)→γPc/χ→γγJ/ψ,γπ+π−,γK+K− and the decays ψ'→ηJ/ψ,π°J/ψ. Nuclear Physics B, 160(2), 426-444. doi:10.1016/0550-3213(79)90067-1

Brandelik, R. "Experimental Results On the Decay Sequences ψ'(3685)→γPc/χ→γγJ/ψ,γπ+π−,γK+K− and the Decays ψ'→ηJ/ψ,π°J/ψ". Nuclear Physics B, 160.2 ( 1979 ): 426-444.