Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
trinh vat » trinh van, trinh luat, sinh vat
trinh han » trinh quan
cau tinh » chau tinh, cuu tinh, cac tinh
cong san » cong tac
phan dau » phan tu, hang dau
phan van » pham van, thanh van, luan van
hoc cau » hoc cao, hoc cac, hoc can

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc cau tinh - canh ((trinh vat) or (trinh han)) nhung cong san ((phan dau) or (phan van))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc cau tinh - canh ((trinh vat) OR (trinh han)) nhung cong san ((phan dau) OR (phan van)).
• Adding a wildcard symbol may retrieve word variants: hoc cau tinh - canh ((trinh vat) or (trinh han)) nhung cong san ((phan dau) or (phan van))*.