Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
chieu sach » chinh sach, chiet tach, chieu sang
trong manh » trong minh, trong anh, trong mach
tuong cua » truong cua, huong cua, thong cua
manh toan » thanh toan, anh tuan, tinh toan
tung cua » trung cua, dung cua, tang cua
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 ((thien hach) or (chieu sach)) - manh ((tung cua) OR (tuong cua)) dung trong manh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thien hach) OR (chieu sach)) - manh ((tung cua) OR (tuong cua)) dung trong manh toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thien hach) or (chieu sach)) - manh ((tung cua) OR (tuong cua)) dung trong manh toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thien hach) or (chieu sach)) - manh ((tung cua) OR (tuong cua)) dung trong manh toan cao*.