Perhaps you should try some spelling variations:
clean development » human development, urban development
pt communication » put communication, et communication, post communication
technology race » technology rate, technology role, technology rich
race relations » trade relations
relations 2.1 » relations 3.1, relations 1, relations _
costs clean » costs clear
2.1 crisis » 3.1 crisis, 2010 crisis, 2011 crisis
crisis pt » crisis _, crisis a
a aortic » _ aortic, _ artic

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

• Adding a wildcard symbol may retrieve word variants: technology race relations 2.1 crisis pt communication costs clean development a aortic.*.