Perhaps you should try some spelling variations:
dua tren » dung tren
tinh lai » tinh lao, tinh hai, minh lai
cham duc » pham duc, cham soc, pham duy
te sach » toc sach
su cham » su pham, tu cham, vu cham
va tinh » may tinh
hieu su » hieu sau, tieu su, hieu so
sach ty » sach y, sach tu, sach thu
dai moi » doi moi
dai hoi » dai hoc, dai hai
ty nang » ky nang, ty xang, ty hang
cuu tre » cua tre, cau tren, cau treo

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 ty nang ((dai hoi) or (dai moi)). hieu su cham duc va tinh lai ((dua tren) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty nang ((dai hoi) OR (dai moi)). hieu su cham duc va tinh lai ((dua tren) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: te sach ty nang ((dai hoi) or (dai moi)). hieu su cham duc va tinh lai ((dua tren) or (cuu tre))*.