Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
dang mat » dang vat, dang mau, dung mat
cham luc » cham soc, nhan luc, cham cuu
hanh tai » hang tai, han tai, hinh tai
tu sach » thu sach, su sach, te sach
duc tre » duoc tren, duc tien
luc van » luoc van, luu van, duc van
sach ky » sac ky, sach y, sach ty
va cham » va chat, va tham
hieu va » lieu va, hieu qua
mat hoi » mai hoi, sat hoi, mat troi
ky dang » ky nang, ky danh
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: tu sach ky dang mat hoi. hieu va cham luc van ((hanh tai) or (thanh tai)) ((duc tre) or (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang mat hoi. hieu va cham luc van ((hanh tai) OR (thanh tai)) ((duc tre) OR (cua tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang mat hoi. hieu va cham luc van ((hanh tai) or (thanh tai)) ((duc tre) or (cua tre))*.