Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham xuc » cam xuc, chat xuc, cham soc
vu sach » vu bach, su sach, vu khach
hanh va » hang va, hanh vi
xuc van » duc van, luc van, vuc van
cua tre » cua te, cuu tre, cua triet
hieu va » hieu qua
nano ma » nang ma, nano va, nano bac
ty nano » tu nano, day nano, tao nano
va cua » va chua, via cua, ca 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: ((vu sach) OR (vay khach)) ty nano ma hoa. ((hieu va) OR (lieu va)) cham xuc van hanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (vay khach)) ty nano ma hoa. ((hieu va) OR (lieu va)) cham xuc van hanh va cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vay khach)) ty nano ma hoa. ((hieu va) OR (lieu va)) cham xuc van hanh va cua tre*.