Perhaps you should try some spelling variations:
cua triet » su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
va hanh » va thanh, va danh, ban hanh
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty nang ma hoa. hieu ve nam thuc ((va hanh) OR (van hanh)) vi ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty nang ma hoa. hieu ve nam thuc ((va hanh) OR (van hanh)) vi ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty nang ma hoa. hieu ve nam thuc ((va hanh) OR (van hanh)) vi ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty nang ma hoa. hieu ve nam thuc ((va hanh) OR (van hanh)) vi ((cua triet) or (cua viet))*.