Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thi nang » thi cong, ki nang, thi hanh
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
va nam » van nam, ha nam, va nay
thu va » thuc va, thue va, tu 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) or (su sach)) thi nang xa hoi. hieu va nam thu va hanh tai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) thi nang xa hoi. hieu va nam thu va hanh tai cua triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) thi nang xa hoi. hieu va nam thu va hanh tai cua triet*.