Perhaps you should try some spelling variations:
nhanh tinh » nhanh thanh, hanh trinh, nhan sinh
thong cong » tong cong, thong thong, phong chong
hieu tinh » chieu tinh, lieu tinh, kieu tinh
doc hieu » toc thieu, hoc thieu, hoc hien
tinh cua » trinh cua, sinh cua, tinh chat
toan tap » toan ban
toan cao » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu tinh - nhanh tinh cua ((thong cong) OR (trong cong)) dan ((toan tap) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu tinh - nhanh tinh cua ((thong cong) OR (trong cong)) dan ((toan tap) OR (toan cao)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu tinh - nhanh tinh cua ((thong cong) OR (trong cong)) dan ((toan tap) or (toan cao))".
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - nhanh tinh cua ((thong cong) OR (trong cong)) dan ((toan tap) or (toan cao))*.