Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
van cam » van lam, van cau, van dam
tuc van » thuc van, truc van, tuc va
vi cua » vai cua, di 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 cam) OR (van nam)) tuc van hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuoc sach)) ky nang xa hoi. hieu ((van cam) OR (van nam)) tuc van hanh vi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuoc sach)) ky nang xa hoi. hieu ((van cam) OR (van nam)) tuc van hanh vi cua vat".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuoc sach)) ky nang xa hoi. hieu ((van cam) OR (van nam)) tuc van hanh vi cua vat*.