Search for the $X(2370)$ and Observation of $\eta_{c}\to\eta\eta\eta^\prime$ in $J/\psi\to\gamma\eta\eta\eta^{\prime}$BESIII CollaborationPhys. Rev. D 103, 012009 (2021)2020DOI 10.1103/PhysRevD.103.012009
Searches for B0 Decays to Eta K0, Eta Eta, Eta' Eta', Eta Phi, and Eta' PhiThe BaBar CollaborationPhys.Rev.D74:051106,20062006DOI 10.1103/PhysRevD.74.051106
Chi C0 and Chi C2 Decays into Eta Eta, Eta Eta', and Eta' Eta' Final StatesAdams, G. S.Phys.Rev.D75:071101,20072006DOI 10.1103/PhysRevD.75.071101
QCD Axial Anomaly Enhances the $\eta \eta^\prime$ Decay of the Hybrid Candidate $\eta_1(1855)$Chen, Hua-XingChin. Phys. Lett. 39, 051201 (2022)2022DOI 10.1088/0256-307X/39/5/051201
Search for B Decays into Eta' Rho, Eta' K*, Eta' Phi, Eta' Omega and Eta' Eta(') at BelleSchümann, J.Phys.Rev.D75:092002,20072007DOI 10.1103/PhysRevD.75.092002
A Possible Gateway to Eta B: Chi {b0}(2P) -> Eta Eta BM. B. VoloshinMod.Phys.Lett.A19:2895-2898,20042004DOI 10.1142/S0217732304016238
$\Eta-\eta^{\prime}$ MixingT. N. PhamPhys. Rev. D 92, 054021 (2015)2015DOI 10.1103/PhysRevD.92.054021