Perhaps you should try some spelling variations:
ngan khung » nganh khong, ngan hang, ngan dung
khung hoc » chung hoc, nhung hoc, thuong hoc
cuu dong » cuu cong, cuu tong, cuu long
dong luc » nang luc
luc ngan » luc nganh, luc nhan, luat ngan
hang tai » hang va, dung tai
tu sach » thu sach, su sach, te sach
so sach » so sanh, bo sach, co sach
hoi tap » hoi dap, hoc tap, hoi tai
va hang » van hang, va nang, va lang
hoa va » hoa van, hoa xa, hoa vo

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 (so sach)) hoi tap, nghien cuu dong luc ngan khung hoc ma hoa va hang tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (so sach)) hoi tap, nghien cuu dong luc ngan khung hoc ma hoa va hang tai.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (so sach)) hoi tap, nghien cuu dong luc ngan khung hoc ma hoa va hang tai*.