Perhaps you should try some spelling variations:
la litterature » a literature
does biologia » de biologia, does biology, di biologia
studies does » studies dress, studies ds, studies der
biologia la » biologia le, biologia alla, biologia de
rats » rate, rays

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "(rats OR rat) gavage studies does biologia la litterature*".