Using Omni's "Advanced Search" function is helpful in finding Indigenous language materials: you can account for different spellings of nations, and you can narrow your search in a number of ways.
Here is information on how to preform an advanced search:
Here is an example of an Advanced Search for Anishinaabemowin materials.
Advanced search gives you the ability to specify date of publication, location, format, language (likely imprecise for most Indigenous languages), material type, place of publication, publication status, content, media, and carrier.
Advanced search does much of the work of using Boolean operators (AND, OR, NOT, and similar commands that broaden or narrow your search) for you. However, you can be more systemic in using Boolean operators in your "regular" searches if you would like. For more information on Boolean operators (and how they work at Queen's) check out the "Introduction to Research" libguide.