This is not an authoritative answer, but my understanding is that the asterisk is intended to be used in conjunction with sources you want to cite that do not have in-line citations in the Bio section using the <ref > and </ ref > tags. If you use the in-line citations, the sources you cite with the tags will appear in the Sources section with a number corresponding to the order in which they appear. If you then want to include additional sources that aren't referenced to any specific thing in the Bio, you can add those in the Sources section, preceded by an asterisk. They will then appear after the numbered sources, but preceded by a bullet. It appears you're not using in-line citations, and I don't recall ever seeing any policy that either encourages or prohibits use of asterisks with the citations as you have them. As far as I can tell, it seems unnecessary, but wouldn't cause any harm.