Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » thien van, lieu va, hieu ve
tu sach » su sach, te sach, tu cach
cam tuc » cam xuc, cam tu, nam thuc
nang co » nang cao, nang doc, nang noi
danh va » doanh va, hanh va, anh va
va danh » va dinh, va dan, va hanh
hieu va » lieu va, hieu qua
va cua » va chua, via cua, ca cua
tuc va » thuc va, truc va, tuc xa
co hoi » co hoc, co loi
cua te » cua tu

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