@article {Liu:2017lpo,
	title = {A Tale of Two Portals: Testing Light, Hidden New Physics at Future $e^+ e^-$ Colliders},
	journal = {JHEP},
	volume = {06},
	year = {2017},
	pages = {077},
	doi = {10.1007/JHEP06(2017)077},
	author = {Jia Liu and Wang, Xiao-Ping and Yu, Felix}
}
