Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van bac » van ban, van bao, dan bac
van hac » van hoc, van ha, van hai
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
danh de » hanh de, dan de, dang de
cua tre » cua te, cuu tre, dua tren

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 ((van bac) or (van hac)) truc va danh de ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ((van bac) OR (van hac)) truc va danh de ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ((van bac) or (van hac)) truc va danh de ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ((van bac) or (van hac)) truc va danh de ((cua tre) OR (cua triet))*.