Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh hoi » hanh thoi, hanh noi, hanh hoa
ban hanh » ban hang
hoi cua » hoi chuc
cam duc » cam xuc, cao duc, nam duoc
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet

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 ty ((nang xa) or (nang ma)) hoi. hieu va ((cam duc) OR (pham duc)) ban hanh hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((nang xa) OR (nang ma)) hoi. hieu va ((cam duc) OR (pham duc)) ban hanh hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty ((nang xa) or (nang ma)) hoi. hieu va ((cam duc) OR (pham duc)) ban hanh hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((nang xa) or (nang ma)) hoi. hieu va ((cam duc) OR (pham duc)) ban hanh hoi cua tre*.