S.R Bommai and Ors Vs Union of India and Ors on 11 March 1994
Citations: [1994 SCALE 2 37], [1994 JT 2 215], [1994 SCALE 2 1], [1994 SCR 2 644], [1994 AIR SC 1918], [1994 SCC 3 1]
Other Source links: https://indiankanoon.org/doc/60799/ or https://www.casemine.com/judgement/in/5609ac9ee4b014971140f544
Earlier case at Karnataka High Court is here.