Perhaps you should try some spelling variations:
doanh thai » doanh tai, doanh thanh, doanh nhan
thai cua » than cua, tai cuc, tri cua
luoc van » luoc can, luoc va, luc van
su sach » so sach, vu sach
luc vay » luc va, luc van
tu nhan » tue nhan, cu nhan, tu ngan
sach ky » sac ky, sach y, sach ty
hieu tu » chieu tu, hieu tuc, hien tu
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: su sach ky ((nang xa) or (nang ma)) hoi. hieu tu nhan ((luc vay) OR (luoc van)) doanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang ma)) hoi. hieu tu nhan ((luc vay) OR (luoc van)) doanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (nang ma)) hoi. hieu tu nhan ((luc vay) OR (luoc van)) doanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (nang ma)) hoi. hieu tu nhan ((luc vay) OR (luoc van)) doanh thai cua tre*.