Perhaps you should try some spelling variations:
thong duong » tuong duong, thong huong, thong thuong
thong dung » thong cong, thong thuong
hoc chinh » hoan chinh, hoc sinh, hoc kinh
hoa chinh » hoan chinh, hoa hinh, hoa thinh
tinh ninh » ninh binh
ninh vat » sinh vat, dinh vat, tinh vat
van phan » van phong, van thanh, luan phan
phan dau » phan tu, hang dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc chinh) or (hoa chinh)) sach - tinh ninh vat ((thong duong) OR (thong dung)) van phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc chinh) OR (hoa chinh)) sach - tinh ninh vat ((thong duong) OR (thong dung)) van phan dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc chinh) or (hoa chinh)) sach - tinh ninh vat ((thong duong) OR (thong dung)) van phan dau".
• Adding a wildcard symbol may retrieve word variants: ((hoc chinh) or (hoa chinh)) sach - tinh ninh vat ((thong duong) OR (thong dung)) van phan dau*.