Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » hoc sach, doc sach, thuoc sach
thuc day » thuc dan, thuc vat
thuc dat » thuc vat, thuc dan, thue dat
sach ly » sach y, sach lo, sach ty
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ly nang ((ma hoi) or (mai hoi)). hieu va cac ((thuc dat) OR (thuc day)) thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ly nang ((ma hoi) OR (mai hoi)). hieu va cac ((thuc dat) OR (thuc day)) thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ly nang ((ma hoi) or (mai hoi)). hieu va cac ((thuc dat) OR (thuc day)) thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ly nang ((ma hoi) or (mai hoi)). hieu va cac ((thuc dat) OR (thuc day)) thanh dai cua tre*.