| − | The '''Hodge star operator''' is a function important in differential geometry and topology. For more information, see the [http://mathworld.wolfram.com/HodgeStar.html MathWorld] entry. | + | The '''Hodge star operator''' is a function important in [[differential geometry]] and [[topology]]. <ref>[http://mathworld.wolfram.com/HodgeStar.html MathWorld]</ref> |