European bond markets have opened to mixed results following word Greece will hold a July 5 referendum over whether or not to accept an accord with its creditors. A flight to safety at the open has pushed yields on core European debt lower: Germany's 10-year yield -20.6bps at 71.4 basis points France's 10-year yield -10 basis points at 1.20% Peripheral European debt is under significant pressure: Greece's 10-year yield +142 basis points at 11.90% Spain 10-year yield +40 basis points at 2.50% Italy 10-year yield +55 basis points at 2.69% Portugal 10-year yield +41 basis points at 3.10% Join the conversation about this story » NOW WATCH: 12 awesome facts about WWE superstar Brock Lesnar