Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh trinh » canh tranh, hanh chinh
hoc thieu » toc thieu, hoc hien
nang cong » nang song, dang cong, hang cong
bang cong » dang cong, bang song, hang cong
trinh va » trinh van, trinh vat, trinh ve
than cau » phan cau, than cap, thanh chau
toan cau » 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 thieu xanh - hanh trinh va ((nang cong) or (bang cong)) dan ((than cau) OR (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh trinh va ((nang cong) OR (bang cong)) dan ((than cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - hanh trinh va ((nang cong) or (bang cong)) dan ((than cau) OR (toan cau))".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh trinh va ((nang cong) or (bang cong)) dan ((than cau) OR (toan cau))*.