T. rex and the Crater of Doom?is under copyright, but the?ebook can be purchased for?Kindle?or?Nook, and can be?downloaded from Google books.

You can also access the original scholarly article, co-authored by Walter Alvarez, his father Luis W. Alvarez, Helen V. Michel, and Frank Asaro,?here?and?here.

Go back to?the main Story of Science page.