Mill, J. S. (1889). A System of Logic: By John Stuart Mill (People's ed.). Longmans.
Chicago-Zitierstil (17. Ausg.)Mill, John Stuart. A System of Logic: By John Stuart Mill. People's ed. London [u.a.]: Longmans, 1889.
MLA-Zitierstil (8. Ausg.)Mill, John Stuart. A System of Logic: By John Stuart Mill. People's ed. Longmans, 1889.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.