Perhaps you should try some spelling variations:
duong thai » duong thi, duong tai, duong hai
vung thai » hung thai, quang thai, luong thai
bang cong » dang cong, bang song, hang cong
cong hach » cong sach, cong thanh, cong khanh
hach toan » thanh toan, manh toan
chi xanh » chi anh, chi danh, chi hanh
toan ban » van ban
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chi xanh - thanh ((vung thai) OR (duong thai)) bang cong hach toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chi xanh - thanh ((vung thai) OR (duong thai)) bang cong hach toan ban".
• Adding a wildcard symbol may retrieve word variants: doi chi xanh - thanh ((vung thai) OR (duong thai)) bang cong hach toan ban*.