Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
cuu thuc » cuu tac
toc sach » hoc sach, doc sach, thuoc sach
nhanh ha » thanh hoa, khanh hoa, nhan va
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa
va cuu » va cau, 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: ((tu sach) or (toc sach)) ky tang ma hoi. hieu va cuu thuc va ((nhanh ha) OR (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky tang ma hoi. hieu va cuu thuc va ((nhanh ha) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky tang ma hoi. hieu va cuu thuc va ((nhanh ha) OR (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky tang ma hoi. hieu va cuu thuc va ((nhanh ha) OR (thanh hai)) cua tre*.