Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
tinh hoai » tinh hai, tinh hoa, thanh hoai
duc tren » duoc tren, dua tren, duc tien
hoai duc » hoa duoc, hong duc, ho duc
hieu van » hieu va, thien van, lieu va
luc may » truc may, phuc may
cau luc » cau truc, cau phuc
van cau » van dau, van hau, van chat
tu sach » thu sach, su sach, te sach
ma hoi » mai hoi, ma hoa, me hoi

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