Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
sach tru » sach truc, sach thu, sach tu
toc sach » hoc sach, doc sach, thuoc sach
lang xa » lang ha, dang xay, lang van
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
nang xa » nang x, nang ma, mang xa
cua tre » cua te, cuu tre, dua tren
hieu va » lieu va, hieu qua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach tru ((nang xa) OR (lang xa)) hoi. hieu va cac tuc van hanh tai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tru ((nang xa) OR (lang xa)) hoi. hieu va cac tuc van hanh tai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tru ((nang xa) OR (lang xa)) hoi. hieu va cac tuc van hanh tai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach tru ((nang xa) OR (lang xa)) hoi. hieu va cac tuc van hanh tai ((cua tre) or (cua triet))*.