Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
cua tre » cua te, cua triet, dua tren
xuc van » duc van, luc van, vuc van
sach tu » sach thu, cach tu, sach ty
hieu ve » hieu va, hieu van
tu nano » truc nano
cuu tre » cau tren, cau treo
ve cam » ve cham, ve cac, va cam
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 tu nano ((o hoi) or (o hai)). hieu ve cam xuc van hanh tai ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nano ((o hoi) OR (o hai)). hieu ve cam xuc van hanh tai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu nano ((o hoi) or (o hai)). hieu ve cam xuc van hanh tai ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: te sach tu nano ((o hoi) or (o hai)). hieu ve cam xuc van hanh tai ((cua tre) OR (cuu tre))*.