You can see the list of six journal titles at the NAfME website. Search the Luther College library catalog for specific titles, or the Academic Search Complete database for articles from five of the six journals. All are available to NAfME members.
The Kodaly Envoy is also searchable in Academic Search Complete and in the Music Index database (for older volumes).
When you are ready to go more in-depth with your research, use these database. Depending on your topic, some databases may be more useful than others. They are listed here in a recommended order.