Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh lay » thanh lap, thanh tay, thanh lam
nam thuc » nam thuoc, am thuc, nam thu
dua tren » dung tren
va triet » va thiet, va trien, ve triet
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va nam » van nam, ha nam, va nay

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x ho. hieu va nam thuc vat thanh lay ((((cua tre) OR (dua tren))) OR (va triet))~.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x ho. hieu va nam thuc vat thanh lay ((((cua tre) or (dua tren))) or (va triet))*.