2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/121582This note is a supplement to the papers: R. V. Gurjar, K. Masuda, M. Miyanishi and P. Russell, Affine lines on affine surfaces and the Makar-Limanov invariant, preprint, 2005, 42p. and T. Kishimoto and H. Kojima, Affine lines on {\bf Q}-homology planes with logarithmic Kodaira dimension $-\infty$, Transform. Groups 11 (2006), no. 4 (to appear). We show the role of group actions in classification of affine lines on {\bf Q}-homology planes.Transform. Groups 11 (2006), no. 4, 14p. (to appear)Algebraic Geometry14R05, 14R20, 14J50text