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 tren
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach ty
cac toc » cac toi, cac nuoc, cac thoi
toc van » hoc van, toc san, tac van
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) OR (sach tu)) nang xa hoi. hieu va cac toc van hanh tai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach tru) OR (sach tu)) nang xa hoi. hieu va cac toc van hanh tai ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach tru) OR (sach tu)) nang xa hoi. hieu va cac toc van hanh tai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: toc ((sach tru) OR (sach tu)) nang xa hoi. hieu va cac toc van hanh tai ((cua tre) or (cua triet))*.