Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hieu van » hieu va, thien van, hieu ve
van hanh » van thanh, ban hanh, van anh
hanh vai » hanh vi, hanh va, hanh tai
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
cam tuc » cam xuc, cam tu, nam thuc
tuc van » thuc van, truc van, tuc va
vai cua » dai cua, hai cua, lai cua

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) or (thuoc sach)) ky nang xa hoi. ((hieu van) OR (lieu va)) cam tuc van hanh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky nang xa hoi. ((hieu van) OR (lieu va)) cam tuc van hanh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ky nang xa hoi. ((hieu van) OR (lieu va)) cam tuc van hanh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky nang xa hoi. ((hieu van) OR (lieu va)) cam tuc van hanh vai cua viet*.