1. Add Müller's publications
2. Add Genesee's publications
3. Check for articles on Serratrice, Sorace, Paoli, Hulk, the other Müller
4. Add biographical articles where warrented - may have been preemptive with Müller's (well-known in the field, but.. surprisingly little third-party sources in Eng.).
   1. Add their publications.
5. Use those you have read to expand on BFLA, acquisition, and transfer effects.
   1. If you haven't already, correct the mistake on the multilingualism page with appropriate refs, ask for discussion first.

I am a student/hobbyist in linguistics, and most of my edits/creations will likely focus around this and closely linked topics.