Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
hanh va » hang va, hanh vi
loc van » luoc van, hoc van, lo van
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty xang, ty hang
va cua » va chua, via cua, ca cua
ve cac » vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ty nang ((mai hoi) or (ma hoa)). hieu ((ve cac) or (va cac)) loc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((mai hoi) OR (ma hoa)). hieu ((ve cac) OR (va cac)) loc van hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((mai hoi) or (ma hoa)). hieu ((ve cac) or (va cac)) loc van hanh va cua tre*.