Inserting references into xtable in Rmd document

Question

I'm embedding an xtable-formatted table into a paper where I need to include citations. For example, check out this table. In the second row it has "Baxter (23)" where the 23 is the reference number. When we made that table, we hard coded the reference number (code here). Is there a direct way to do this within knitr if we put the table inside the manuscript Rmd file? When I do this and instead of the 23 put" [@SchlossXXXX]" it renders as [@SchlossXXXX].