The words "Unity and Integrity of the Nation" were incorporated in the Preamble  of The Constitution of India by which Amendment? 

·         The 42nd Amendment of Indian Constitution is also known as the “mini-constitution” as many parts of constitution like preamble and even the Amending clause was amended by this Amendment- ·         By this Amendment only the description of India from a "sovereign democratic republic" to a "sovereign, socialist secular democratic republic", and also changed the words "unity of the nation" to "unity and integrity of the nation". This Amendment act was enacted during National Emergency in India and is considered as the most controversial amendment in constitutional history of India.