I am looking at reliable source to actually get the market exchange rate between BTC/USD, and hopefully BTC/EUR and BTC/CAD as well.

This is for automation purposes, so that can process a fair exchange rate according to at least several reliable source.  I do NOT want to rely on only one source.

Does anyone know of any such source, where the data can be provided though an, API, in plain text, or any mean that is meant to be read "not on a web page"?