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
dai hoi » dai hoc, dai hai, dai moi
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 » 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: ((toc sach) or (hoc sach)) ly nang ((ma hoi) or (dai 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 (dai 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 (dai hoi)). hieu va cac truc va thanh dai cua tre*.