Perhaps you should try some spelling variations:
tang dai » tang tai, tang dan, lang dai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
tai cuu » tai buu, tai cua, thai cua
va hanh » van hanh, va thanh, va danh
dai moi » doi moi, dai hoi
ky tang » ky nang, ky dang, kho tang
va cam » va cham, va cac, va cao
ve cai » va cai, ve cac, ve tai
luc va » duc va, tuc va, loc va

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