Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phung cong
cua phuong » cuu phuong, cuc phuong, luan phuong
trinh chat » tinh chat, trinh luat, trinh han
hieu sang » chieu sang, hieu lang, hieu quang
hoang van » hang va
trong cho » trong tho, trong co, rong cho
doc hieu » toc thieu, hoc thieu, hoc hien
cong ban » cong bang, cong san, cong tan
tran cao » toan cao, tran chau, trang cho
van cua » vang cua, ban cua, dan cua

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 sang - hoang van cua phuong cong ban ((((tran cao) or (trinh chat))) or (trong cho))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - hoang van cua phuong cong ban ((((tran cao) OR (trinh chat))) OR (trong cho)).
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - hoang van cua phuong cong ban ((((tran cao) or (trinh chat))) or (trong cho))*.