Perhaps you should try some spelling variations:
peter bratt » peter brett, peter pratt, peter bryant
peter gray » peter bray, peter ray, peter grant
peter graf » peter grant
bioengineer » bioengineers, bioengineered, bioengineering

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: ((((peter gray) OR (peter graf))) OR (peter bratt)) (bioengineer).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((peter gray) OR (peter graf))) or (peter bratt)) (bioengineer)".
• Adding a wildcard symbol may retrieve word variants: ((((peter gray) OR (peter graf))) or (peter bratt)) (bioengineer)*.