Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
dinh cuu » dinh chi
tinh cua » trinh cua, sinh cua, tinh chat
cong van » cong vang, cong san, song van
van than » van thanh, van thang, van tuan
than tap » toan tap, han tap, phan tap

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 xanh - hoang ((dinh cuu) or (tinh cua)) thong cong van than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - hoang ((dinh cuu) OR (tinh cua)) thong cong van than tap.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hoang ((dinh cuu) or (tinh cua)) thong cong van than tap*.