Perhaps you should try some spelling variations:
"maternal nutrition" » "material nutrition", "materials nutrition", "internal nutrition", "maternal nutritiva", "materiall nutrition"
"external nutrition" » "external nutritiva", "internal nutrition"
"integral nutrition" » "integral nutritiva"
"materna nutritivo" » "material nutritivo", "materna nutritiva"

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 (\"external nutrition\"))) OR (\"integral nutrition\"))) OR (((\"materna nutritivo\") OR (\"materia nutricion\"))))~".
• Removing quotes may allow a broader search: (((((( maternal nutrition ) OR ( external nutrition ))) OR ( integral nutrition ))) OR ((( materna nutritivo ) OR ( materia nutricion ))))~.
• Adding a wildcard symbol may retrieve word variants: (((((("maternal nutrition") OR ("external nutrition"))) OR ("integral nutrition"))) OR ((("materna nutritivo") OR ("materia nutricion"))))*.