Perhaps you should try some spelling variations:
"maternal nutrition" » "materna nutrition", "materials nutrition", "materia nutrition", "maternal nutritivo"
"material nutrition" » "material nutritivo", "materia nutrition"
"material nutritiva" » "materia nutritiva"
"material nutricion" » "materia nutricion"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"maternal nutrition\") OR (((((\"material nutrition\") OR (\"material nutritiva\"))) OR (\"material nutricion\"))))~".
• Removing quotes may allow a broader search: (( maternal nutrition ) OR ((((( material nutrition ) OR ( material nutritiva ))) OR ( material nutricion ))))~.
• Adding a wildcard symbol may retrieve word variants: (("maternal nutrition") OR ((((("material nutrition") OR ("material nutritiva"))) OR ("material nutricion"))))*.