Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dua tren » dung tren
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua thep
tu sach » thu sach, su sach, te sach
cac tuc » cac toc, cac tu, cac tac
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
tuc va » thuc va, truc va, tuc xa
ve cac » va cac, vien cac
dan vi » doan vi, don vi, dan va
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang xa hoi. hieu ve cac tuc va dan vi ((((cua tre) OR (dua tren))) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ve cac tuc va dan vi ((((cua tre) OR (dua tren))) OR (cua triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ve cac tuc va dan vi ((((cua tre) OR (dua tren))) or (cua triet))*".