Explanation:

- 'The Indian Struggle 1920 - 1942' was authored by Subhas Chandra Bose. This book provides an analysis of the Indian freedom struggle during those years.

- Vinayak Damodar Savarkar was an Indian independence activist and a proponent of Hindutva. He wrote books like 'The First War of Indian Independence.'

- Vallabhbhai Patel, also known as Sardar Patel, was a key political and social leader in India but wasn't known for this kind of book.

- Sarat Chandra Bose was the brother of Subhas Chandra Bose. Although influential, he did not author the book in question.