Perhaps you should try some spelling variations:
otto gellert » otto heller, otto mueller
otto muller » otto mueller, otto heller
water polo » water pools, water policy, water people
water poet » water power, water part

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: ((otto muller) OR (otto gellert)) (((water polo) OR (water poet))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((otto muller) or (otto gellert)) (((water polo) OR (water poet)))".
• Adding a wildcard symbol may retrieve word variants: ((otto muller) or (otto gellert)) (((water polo) OR (water poet)))*.