(en) Maurice L. Blackmon, John M. Wallace, Ngar-Cheung Lau, Steven L. Mullen, « An Observational Study of the Northern Hemisphere Wintertime Circulation », Journal of the Atmospheric Sciences, vol. 34, no 7, , p. 1040–1053 (DOI10.1175/1520-0469(1977)034<1040:AOSOTN>2.0.CO;2).