Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
cua triet » cua viet, su triet, va triet
thanh di » thanh doi, thanh de, thanh do
nang hoc » nang doc, nang luc, dong hoc
nam thuc » nam thuoc, am thuc, nam thu
thuc van » thuc vat, thuc dan, thuc va
su viet » so viet
nang ho » nang co, tang ho, nang cao
hieu ve » hieu va, hieu van
su sai » su tai, su hai, su dai
sai ky » sac ky
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sai ky ((nang ho) OR (nang hoc)) hoi. hieu ve nam thuc van thanh di ((cua triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky ((nang ho) OR (nang hoc)) hoi. hieu ve nam thuc van thanh di ((cua triet) OR (su viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky ((nang ho) OR (nang hoc)) hoi. hieu ve nam thuc van thanh di ((cua triet) or (su viet))*".