किस लेखक ने प्रभावशाली पुस्तक 'Jharkhand: Castle Over the Grave' लिखी है, जो झारखंड क्षेत्र के सामाजिक-आर्थिक शोषण पर एक आलोचनात्मक ऐतिहासिक दृष्टिकोण प्रस्तुत करती है?

The Dandi March, also known as the Salt Satyagraha, was led by which influential leader?

Which act formally granted independence to India, marking the end of British rule?

Who was the key figure in establishing the Indian National Congress?