Perhaps you should try some spelling variations:
tinh hai » tinh thai, tinh chat, trinh han
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
luc may » truc may, phuc may
cau luc » cau truc, cau phuc
van cau » van dau, van hau, van chat
cu tren » tu tren, dua tren
ma hoi » mai hoi, ma hoa, me hoi
hai cu » hai cua, hai chu, hai cuc

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) or (hoc sach)) ky nang ((ma hoi) or (xa hoi)). hieu van cau luc may tinh hai cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky nang ((ma hoi) OR (xa hoi)). hieu van cau luc may tinh hai cu tren.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky nang ((ma hoi) or (xa hoi)). hieu van cau luc may tinh hai cu tren*.