Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
va thanh » gia thanh, ban thanh, va tinh
cac truc » cau truc, cac tru, cac trung
mai hoi » mai khoi, dai hoi, lai hoi
truc va » thuc va, thuc vat, trung va
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
ly nang » ky nang, ly hang, ly vang
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) OR (hoc sach)) ly nang ((ma hoi) or (mai hoi)). hieu va cac truc va thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ly nang ((ma hoi) OR (mai hoi)). hieu va cac truc va thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) ly nang ((ma hoi) or (mai hoi)). hieu va cac truc va thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) ly nang ((ma hoi) or (mai hoi)). hieu va cac truc va thanh dai cua tre*.