Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
danh vai » danh sai, danh va, doanh van
su sach » so sach, vu sach
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
va nam » van nam, ha nam, va nay
thu va » thuc va, thue va, tu va
o hoi » co hoi, o hoc, o hai
thiet » thieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((ty nang) OR (ky nang)) o hoi. hieu va nam thu va danh vai ((cua triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty nang) OR (ky nang)) o hoi. hieu va nam thu va danh vai ((cua triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty nang) OR (ky nang)) o hoi. hieu va nam thu va danh vai ((cua triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty nang) OR (ky nang)) o hoi. hieu va nam thu va danh vai ((cua triet) or (va thiet))*.