Perhaps you should try some spelling variations:
physiological sleep » physiological stress, physiological states, physiological system
physiological blue » physiological values, physiological bases, physiological based
der tier » der tiere, der tiger, der titel
zur dem » zur de, zur den, fur dem
fur des » fur den, fur das, fur dein

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: monographien ((zur dem) OR (fur des)) gesamtgebiet der ((physiological sleep) OR (physiological blue)) pflanzen und der tier.
• The words AND, OR and NOT may confuse the search; try adding quotes: "monographien ((zur dem) or (fur des)) gesamtgebiet der ((physiological sleep) OR (physiological blue)) pflanzen und der tier".
• Adding a wildcard symbol may retrieve word variants: monographien ((zur dem) or (fur des)) gesamtgebiet der ((physiological sleep) OR (physiological blue)) pflanzen und der tier*.