Well, depending on how they were entered originally', you may have to do some cutting and pasting, but you can avoid repeating pre-existing sources. If you put a short reference such as "<ref>Some Book p355</ref>" in-line in the biio it will show up in the bio as  and under sources like 1. Some book p355. In some cases you may want to elaorate more and put a more complete citation / source at the bottom of the numbered sources by entering * The Tildon Big Book (c) 1926 Some publisher, etc." These start out under the ==source== thingee. and the numbered sources magically appear above them. This is the best way to deal with sources you're using a lot and need to show the page number and also the publication details. It may not be the ideal way to do things, and I may eventually edit things to make them more technically correct, but someone wanting to find a source should be able to do it.
So, paste your existing sources either between refs in the bio or star them below the sources and use a short reference in the bio.