Change

<ref name="foo"'>

to

<ref name="foo">

Examples:

Army of God (United States): <ref name="Armed"'>
CoppaFeel!: <ref name="The Mirror, 'I love boobs: Mel B goes topless and reveals she used to fondle the Spice Girls"'>
Prince Aimone, Duke of Apulia: <ref name="ghda"'>
Rafael Alberti: <ref name="Morris Darkness"'>
Random subspace method: <ref name="ho1995"'>
Till Lindemann: <ref name="1999"Aprillind"'>, <ref name="rosen"2011"'>, <ref name="guardian"201$"'>, <ref name="MusicExp"1997"'>, <ref name="putnam"2013"'>, <ref name="Berlinski"2005"'>, <ref name="bildde"2014"'>, <ref name="kaiser"2014"'>