Perhaps you should try some spelling variations:
nang chat » nang phat, nang cham, nang suat
van hanh » van thanh, ban hanh, van anh
cham tuc » nham thuc, pham thuc, tham thuc
tu sach » thu sach, su sach, te sach
sach ly » sach y, sach lo, sach ty
va hanh » va thanh, va danh, ban hanh
va cham » va chat, va tham
hieu va » lieu va, hieu qua
su tien » su kien, su hien, tu tieng
ki su » ky su

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 ly ((nang chat) OR (nang cao)) hoc. hieu va cham tuc ((va hanh) or (van hanh)) ki su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ly ((nang chat) OR (nang cao)) hoc. hieu va cham tuc ((va hanh) OR (van hanh)) ki su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ly ((nang chat) OR (nang cao)) hoc. hieu va cham tuc ((va hanh) or (van hanh)) ki su tien".
• Adding a wildcard symbol may retrieve word variants: tu sach ly ((nang chat) OR (nang cao)) hoc. hieu va cham tuc ((va hanh) or (van hanh)) ki su tien*.