Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
su sach » so sach, vu sach
tai cuu » tai cuc, tai buu, tai cua
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
dan hoi » dan hoc, dai hoi, van hoi
dan moi » ban moi, dai moi, dan mon
ky tang » ky nang, ky dang, kho tang
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
ve cai » va cai, ve cac, ve tai

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 ky tang ((dan moi) OR (dan hoi)). hieu ((ve cai) or (va cam)) luc va hanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky tang ((dan moi) OR (dan hoi)). hieu ((ve cai) OR (va cam)) luc va hanh tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky tang ((dan moi) OR (dan hoi)). hieu ((ve cai) or (va cam)) luc va hanh tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky tang ((dan moi) OR (dan hoi)). hieu ((ve cai) or (va cam)) luc va hanh tai cuu tre*.