Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, nghiep nganh
vien thanh » viet thanh, tien thanh, dien thanh
canh trinh » canh tranh, hanh trinh, canh tinh
nhung cong » dung cong, thong cong, hang cong
hieu manh » chieu xanh, dieu hanh, hien hanh
cong tinh » cong trinh, cong vinh, long tinh
trinh va » trinh van, trinh vat, trinh ve
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((((hieu nganh) OR (hieu manh))) or (vien thanh)) - canh trinh va nhung cong tinh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((((hieu nganh) OR (hieu manh))) OR (vien thanh)) - canh trinh va nhung cong tinh toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((((hieu nganh) OR (hieu manh))) or (vien thanh)) - canh trinh va nhung cong tinh toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((((hieu nganh) OR (hieu manh))) or (vien thanh)) - canh trinh va nhung cong tinh toan cao*.