Perhaps you should try some spelling variations:
peter bratt » peter brett, peter pratt, peter bryant
peter gray » peter ray, peter grant, peter murray
peter bray » peter brady, peter ray, peter brian
peter graf » peter grant

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