Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
thanh de » hanh de, thanh ve, thanh do
va thanh » gia thanh, ban thanh, va tinh
cam tuc » cam xuc, nam thuc, dam thuc
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
cam tu » cam thu, nam tu, dam tu
de cua » le cua, te cua, dieu 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 (thu hoach)) ky nang ma hoi. hieu van ((cam tuc) OR (cam tu)) va thanh de cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu hoach)) ky nang ma hoi. hieu van ((cam tuc) OR (cam tu)) va thanh de cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu hoach)) ky nang ma hoi. hieu van ((cam tuc) OR (cam tu)) va thanh de cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu hoach)) ky nang ma hoi. hieu van ((cam tuc) OR (cam tu)) va thanh de cua viet*.