Perhaps you should try some spelling variations:
sach hoi » sach doi, sach moi, cach thoi
sach tao » sach dao, sach bao, sach tai
van hanh » van thanh, ban hanh, van anh
hanh va » hang va, hanh vi
xuc van » duc van, luc van, vuc van
hieu ve » hieu va, hieu van
bac hoi » bac ho, bac hoc, bach hoa
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach tao) or (lanh dao)) nano ((bac hoi) or (sach hoi)). hieu ve cam xuc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach tao) OR (lanh dao)) nano ((bac hoi) OR (sach hoi)). hieu ve cam xuc van hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach tao) or (lanh dao)) nano ((bac hoi) or (sach hoi)). hieu ve cam xuc van hanh va cua tre*.