Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
thanh le » thinh le, thanh ve, thanh de
thanh te » thanh ve, thanh de, thanh tu
cam tuc » cam xuc, cam tu, nam thuc
van cam » van nam, van lam, van cau
tu sach » su sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa
y nang » ky nang, ly nang, v nang

You may be able to get more results by adjusting your search query.

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