This is from today’s news in Science. The full citation is:

M. Bowling, N. Burch, M. Johanson, O. Tammelin, “Heads-up limit hold’em poker is solved”, Science, 9 January 2015, 347(6218), 145-149, http://dx.doi.org/10.1126/science.1259433.

See also a University of Alberta site where you can play against their algorithm if interested.

There’s also an overview by T. Sandholm, “Solving imperfect information games“.