Hi Hemal,It is totally understandable that some of us cannot always spend a lot of time online whenever we get busy from other things. I found your blog from a postcard/stamp site I just visited. I read some information about Indian Navy ships, and found out that the Indian Navy is one of the largest navies in the world! Awesome!I checked out an online stamp catalogue that I always visit, searched for the stamps you have here from India, and found the exact same stamps, which were issued in 2011, December 19. The four-set stamp is entitled President’s Fleet Review, Mumbai.