Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, hang cong
hoc thieu » toc thieu, hoc hien
trinh vat » trinh van, trinh luat, sinh vat
vat nhung » va nhung, vap nhung, vai nhung
tan toan » tan tran, dan toan, tam toan
van toan » van tuan, van tan, van thanh
tap toan » tap doan, tap quan, bai toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu xanh - hanh trinh vat nhung cong ((((tan toan) OR (van toan))) or (tap toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh trinh vat nhung cong ((((tan toan) OR (van toan))) OR (tap toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - hanh trinh vat nhung cong ((((tan toan) OR (van toan))) or (tap toan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh trinh vat nhung cong ((((tan toan) OR (van toan))) or (tap toan)) cau*.