Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cau triet » cau trieu, su triet, va triet
hanh van » thanh van, khanh van, hanh va
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
cam duc » cam xuc, cao duc, pham duc
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
van cam » van nam, van lam, van cau
ha hoi » hoa hoi, ha noi, xa 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 ((ky lang) or (ky dang)) ha hoi. hieu van cam duc van hanh van ((cau triet) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky dang)) ha hoi. hieu van cam duc van hanh van ((cau triet) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky lang) or (ky dang)) ha hoi. hieu van cam duc van hanh van ((cau triet) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky dang)) ha hoi. hieu van cam duc van hanh van ((cau triet) OR (cua triet))*.