Perhaps you should try some spelling variations:
segmental signatures » elemental signatures, elemental signature, dental signatures
segment features » salient features, element features, recent features
segment feature » segments feature, segmental features, salient feature

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: line ((((segment feature) OR (segment features))) OR (segmental signatures)) analysis.
• Adding a wildcard symbol may retrieve word variants: line ((((segment feature) or (segment features))) or (segmental signatures)) analysis*.