Perhaps you should try some spelling variations:
professional practical » professionals practical, professional practice, professional practices
profesional services » professional services, professional service, professional series
channels formation » channel formation, channels information, channel information

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: channels formation ((profesional services) OR (professional practical)).
• Adding a wildcard symbol may retrieve word variants: channels formation ((profesional services) or (professional practical))*.