Perhaps you should try some spelling variations:
verbal communication » nonverbal communication, virtual communication, oral communication
communication across » communication cross, communicating across, communication about
grade developpement » trade developement, trade development, de developpement
developpement de » developpement des, developpement durable
apologien der » typologien der, apologie des, ideologien der
der variation » de variation, does variation, die variation
across grade » across gender

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

• Adding a wildcard symbol may retrieve word variants: apologien der variation _ etc verbal communication across grade developpement de l'afrique.*.