Perhaps you should try some spelling variations:
chet duoc » che duoc, cho duoc, che quoc
cau tren » cu tren, dau tren, ca tren
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
duoc va » nuoc va, duc va, duoc ma
hieu ve » hieu va, hieu van
te sach » toc sach
ve chet » ve chat, ve che, se chet
y nang » ky nang, ly nang, v nang
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o 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 y nang ((o hoi) or (o hai)). hieu ve chet duoc va hanh vi ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((o hoi) OR (o hai)). hieu ve chet duoc va hanh vi ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((o hoi) or (o hai)). hieu ve chet duoc va hanh vi ((cua tre) or (cau tren))*.