http://press.cern/press-releases/2016/12/alpha-experiment-observes-light-spectrum-antimatter-first-time [press.cern]
http://www.nytimes.com/aponline/2016/12/19/world/europe/ap-eu-antimatter-experiment.html [nytimes.com]
http://www.npr.org/sections/thetwo-way/2016/12/19/506134622/scientists-blast-antimatter-atoms-with-a-laser-for-the-first-time [npr.org]
Observation of the 1S–2S transition in trapped antihydrogen [nature.com] (DOI: 10.1038/nature21040) (DX [doi.org])