Perhaps you should try some spelling variations:
thieu tinh » trieu tinh, chieu tinh, thien tinh
canh trinh » canh tranh, hanh trinh, canh tinh
hoc thieu » toc thieu, hoc hien
trinh mat » trinh vat, trinh may, trinh mau
mat trong » vat trong, dat trong, mat thong
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
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 tinh - canh trinh mat trong ((cong ban) or (cong san)) ((than cau) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu tinh - canh trinh mat trong ((cong ban) OR (cong san)) ((than cau) OR (toan cau)).
• Adding a wildcard symbol may retrieve word variants: hoc thieu tinh - canh trinh mat trong ((cong ban) or (cong san)) ((than cau) or (toan cau))*.