The citation advantage for open access papers was analysed in this paper from 2018.
Piwowar H, Priem J, Larivière V, Alperin JP, Matthias L, Norlander B, Farley A, West J, Haustein S. 2018. The state of OA: a large-scale analysis of the prevalence and impact of Open Access articles. PeerJ 6:e4375 https://doi.org/10.7717/peerj.4375
Open access papers also have more downloads compared with non-open access papers.
Comparison of accumulation page view between OA and non-OA articles Wang, X., Liu, C., Mao, W. et al. Scientometrics (2015) 103: 555. https://doi.org/10.1007/s11192-015-1547-0
Open access books also have more citations, downloads and usage than non open access books.
Springer Nature white paper The OA effect: How does open access affect the usage of scholarly books? November 2017.