Omnibus editions of Agatha Christie
So I visited a bookstore last weekend and found a few "omnibus" editions by Christie (1920s, 1960s, etc). Later I tried to google for a complete list of all such omnibus but did not find one I was looking for. There are random mentions of a few titles here and there on several blogs, but I am looking for all the omnibus titles till date in one place. Can someone kindly help me out if they already know of such a list? If not then we can prepare one.