Sample selection bias as a specification error. Heckman JJ. JJ Heckman - Econometrica: Journal of the econometric society, 1979 - JSTOR GSID: GG1OPAycdwYJ
Statistical analysis with missing data. Little RJA, Rubin DB. RJA Little, DB Rubin - 2019 - books.google.com GSID: 1QiqAk4vRbMJ
