Here are some quotes and links:

" In a statement issued later Saturday, Sanders added: "As is the case virtually every day, Donald Trump is showing the American people that he is a pathological liar." "

http://www.cnn.com/2016/03/12/politics/bernie-sanders-donald-trump/index.html

"Bernie Sanders denounced Donald Trump as a “pathological liar” who leads a “vicious movement” on Saturday,"

http://www.theguardian.com/us-news/2016/mar/12/sanders-attacks-trump-vicious-campaign-chicago-backlash

"Sanders Unloads On 'Pathological Liar' Trump"

http://www.huffingtonpost.com/entry/bernie-sanders-unloads-on-donald-trump_us_56e4847ae4b0860f99d9475f