@article {2022MNRAS.510.4998Z,
	title = {ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions - IV. Radio recombination lines and evolution of star formation efficiencies},
	journal = {\mnras},
	volume = {510},
	number = {4},
	year = {2022},
	month = {mar},
	pages = {4998-5008},
	keywords = {Astrophysics - Astrophysics of Galaxies, H II regions, ISM: clouds, radio lines: ISM, stars: formation},
	doi = {10.1093/mnras/stab2733},
	author = {C. Zhang and Evans, Neal J. and T. Liu and Wu, J. -W. and Ke Wang and Liu, H. -L. and Zhu, F. -Y. and Ren, Z. -Y. and Dewangan, L.~K. and Lee, Chang Won and Li, Shanghuo and Bronfman, L. and Tej, A. and D. Li}
}
