Be careful not to box yourself into a concrete search term for your topic. Think of synonyms for your subject - broader terms, related terms, and narrower terms. Using this strategy will guarantee a wider selection of materials. Be aware, too, that some search terms may be uncomfortable to think or say out loud - but could yield possible results.
"Exceptionalities" is a broad term that doesn't even begin to capture the myriad experiences of individuals of have differing abilities. Take a look at winners of the Schneider Family Book Award as an initial search and for keyword ideas.
Possible search terms: wheelchairs, children with disabilities, physical disability, people with disabilities, deaf, blind, cerebral palsy