AYAKO KUBOTA, “INVARIANT HILBERT SCHEME RESOLUTION OF POPOV'S SL(2)-VARIETIES”, Transformation Groups, 26:4 (2021), 1365
Ayako Kubota, “On minimality of the invariant Hilbert scheme associated to Popov's $\mathit{SL}(2)$-variety”, Proc. Japan Acad. Ser. A Math. Sci., 96:7 (2020)
V. Batyrev, F. Haddad, “On the Geometry of $\operatorname{SL}(2)$-Equivariant Flips”, Mosc. Math. J., 8:4 (2008), 621–646
Д. И. Панюшев, “Канонический модуль аффинного нормального квазиоднородного $SL_2$-многообразия”, Матем. сб., 182:8 (1991), 1211–1221 ; D. I. Panyushev, “The canonical module of a quasihomogeneous normal affine $SL_2$-variety”, Math. USSR-Sb., 73:2 (1992), 569–578