Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
loc va » hoc va, luc va
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, 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: thuat sach v nang ((o hoi) OR (o hoc)). hieu va tham ((duc va) or (loc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach v nang ((o hoi) OR (o hoc)). hieu va tham ((duc va) OR (loc va)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach v nang ((o hoi) OR (o hoc)). hieu va tham ((duc va) or (loc va)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach v nang ((o hoi) OR (o hoc)). hieu va tham ((duc va) or (loc va)) hanh vi cua tre*.