Perhaps you should try some spelling variations:
khanh hoa » thanh hoa, hang hoa
cau thuc » cau truc, cuu thuc, can thuc
toc sach » hoc sach, doc sach, thuoc sach
nhanh ha » thanh hoa, thanh hai, nhan va
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
va cau » van cau, va cac, va dau
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ky tang ma hoi. hieu va cau thuc vat ((nhanh ha) OR (khanh hoa)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky tang ma hoi. hieu va cau thuc vat ((nhanh ha) OR (khanh hoa)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky tang ma hoi. hieu va cau thuc vat ((nhanh ha) OR (khanh hoa)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky tang ma hoi. hieu va cau thuc vat ((nhanh ha) OR (khanh hoa)) cua tre*.