Perhaps you should try some spelling variations:
thiet hach » thien hach, thuyet hach, thiet hai
thanh tung » thanh cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trong san » trong cac, cong san, dong san
tung cap » trung cap, cung cap, thong cap
cap dung » ap dung, cao dung, chan dung
khau cap » khau tap, khau nhap, khau tai
khau cao » khau hao, nha cao, khau tai
khan cap » khan ap, than cap, khoan cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thiet hach - thanh tung cap dung trong san ((((khau cap) or (khau cao))) or (khan cap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet hach - thanh tung cap dung trong san ((((khau cap) OR (khau cao))) OR (khan cap)).
• Adding a wildcard symbol may retrieve word variants: hoc thiet hach - thanh tung cap dung trong san ((((khau cap) or (khau cao))) or (khan cap))*.