Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh van » thanh san, thanh toan, thanh phan
va triet » va thiet, va trien, ve triet
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
va cau » van cau, va cac, va dau
va cuu » va chu, va huu

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 lang xa hoi. hieu ((va cuu) or (va cau)) thuc vat thanh van ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. hieu ((va cuu) OR (va cau)) thuc vat thanh van ((cua tre) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky lang xa hoi. hieu ((va cuu) or (va cau)) thuc vat thanh van ((cua tre) or (va triet))*.