Perhaps you should try some spelling variations:
vien dai » hien dai
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
tai cua » thai cua, tai cuc, tri cua
xuc van » duc van, luc van, xuc ban
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
nang xa » lang xa, nang ma, mang xa
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang xa) or (nang x)) hoi. hieu ((ve cam) or (vien dai)) xuc van hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang x)) hoi. hieu ((ve cam) OR (vien dai)) xuc van hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang x)) hoi. hieu ((ve cam) or (vien dai)) xuc van hanh tai cua tre*.