We expect there may be other underground experiments or establishments throughout the United States already in operation, but because of the legality of it, they are keeping hush. (fooddrink-magazine.com)
A host of experiments searching for dark matter, including the Large Hadron Collider, many underground experiments and several space missions, have failed to see anything... (newscientist.com)
The scientists spearheaded giant underground experiments that revealed that the elusive particles morph from one variety into another. (sciencenews.org)