Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hanh vii » hanh voi, hanh va, hanh noi
mai khoi » mai khoa, tai khoa, cac khoi
cau luc » cau truc, cau phuc
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
mai hoi » dai hoi, lai hoi, mai doi
ky tang » ky nang, ky dang, kho tang
luc va » duc va, tuc va, loc va
va cau » van cau, va cac, va dau

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 ((mai hoi) or (mai khoi)). lieu va cau luc va ((hanh vii) or (hanh vi)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ((mai hoi) OR (mai khoi)). lieu va cau luc va ((hanh vii) OR (hanh vi)) cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang ((mai hoi) or (mai khoi)). lieu va cau luc va ((hanh vii) or (hanh vi)) cau tren*.