 Alliancebernstein L.P. lessened its stake in Houghton Mifflin Harcourt Co NASDAQ:HMHC by 1.9 in the 1st quarter, according to its most recent filing with the SEC. The firm owned 8,464,181 shares of the business services providers stock after selling 163,516 shares during the quarter. Alliancebernstein L.P. owned 0.07 of Houghton Mifflin Harcourt worth 15,913,000 as ... 