Citation after etc word
The full stop indicates that etc. is a contraction of et cetera. This means that the citation should come after the dot:


  etc. [1]


If this is the end of the sentence, put a second full stop after the citation:


  etc. [1].


As an aside, my old English teacher told me that using etc. is bad form; if you have other things to list, be explicit and list them. If not, don't waste space with the pointless filler. (However, I myself have often broken this rule.)