1. Edward Sapir's personal website

    http://emuseum.mnsu.edu/information/biography/pqrst/sapir_edward.html

     2. Franz Boas's personal website

    http://emuseum.mnsu.edu/information/biography/abcde/boas_franz.html

    3. Leonard Bloomfield's personal website

    http://cognet.mit.edu/MITECS/Entry/langendoen

      http://www.xrefer.com/entry/441234

      http://beaugrande.bizland.com/Bloomfield.ht

      4. Levels in American Structuralist phonology                                                                

    http://www.phon.ox.ac.uk/~jcoleman/rules.htm