Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
danh vai » danh sai, danh va, doanh van
doanh va » doan va, doanh tai, doanh cua
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
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 ky dang xa hoi. hieu va cac duc va ((danh vai) or (doanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky dang xa hoi. hieu va cac duc va ((danh vai) OR (doanh va)) cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky dang xa hoi. hieu va cac duc va ((danh vai) or (doanh va)) cua tre*.