Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
pham xay » phan xay, pham van, pham tai
pham day » phap day, pham duy, pham dac
va vanh » va van, va danh, va hanh
sach ty » sach tu, sach thu, xach tay
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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: tu ((sach y) OR (sach ty)) nang o hoi. lieu va ((pham day) OR (pham xay)) va vanh dai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach y) or (sach ty)) nang o hoi. lieu va ((pham day) OR (pham xay)) va vanh dai cua te~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach y) or (sach ty)) nang o hoi. lieu va ((pham day) OR (pham xay)) va vanh dai cua te*.