Perhaps you should try some spelling variations:
cham quoc » chuan quoc, han quoc, cham soc
kho tang » cao tang
lan hanh » ban hanh, van hanh, lan anh
quoc lan » quoc ban, nuoc luan, quoc quan
hieu van » hieu va, thien van, lieu va
cac kho » cac khoi, cac khoa, cac khu
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
ma hoi » mai hoi, xa hoi, me hoi
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac kho tang ((ma hoi) OR (ma hoa)). ((hieu ve) OR (hieu van)) cham quoc lan hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac kho tang ((ma hoi) OR (ma hoa)). ((hieu ve) or (hieu van)) cham quoc lan hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu cac kho tang ((ma hoi) OR (ma hoa)). ((hieu ve) or (hieu van)) cham quoc lan hanh vi cua tre*.