Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
dinh cuu » dinh chi
tinh cua » trinh cua, tinh chat, tranh cua
sinh cua » manh cua, sinh va
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) OR (sinh cua)))) nhung 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) OR (sinh cua)))) nhung cong van than tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hoang ((dinh cuu) or (((tinh cua) OR (sinh cua)))) nhung cong van than tap".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hoang ((dinh cuu) or (((tinh cua) OR (sinh cua)))) nhung cong van than tap*.