Perhaps you should try some spelling variations:
"spectral types with belligerents" » "special types with belligerents", "several types with belligerents", "structural types with belligerents"
"neutral types with belligerents" » "neutral type with belligerents", "neuronal types with belligerents", "several types with belligerents"
"special type with belligerents" » "special types with belligerents", "special topic with belligerents"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("neutral types with belligerents") OR ((("spectral types with belligerents") OR ("special type with belligerents")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"neutral types with belligerents\") or (((\"spectral types with belligerents\") OR (\"special type with belligerents\"))))".
• Removing quotes may allow a broader search: (( neutral types with belligerents ) or ((( spectral types with belligerents ) OR ( special type with belligerents )))).
• Adding a wildcard symbol may retrieve word variants: (("neutral types with belligerents") or ((("spectral types with belligerents") OR ("special type with belligerents"))))*.