Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
trung tuan » trung thanh, trung tam, tran tuan
bang duong » bang suong, bang tuong, tang duong
duong sinh » duong minh, duong manh, trong sinh
trung cua » truong cua, trung cap, dung cua
sinh toan » tinh toan, hinh toan, minh toan
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 sach) or (thien hach)) - hanh ((trung cua) OR (trung tuan)) bang duong sinh toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - hanh ((trung cua) OR (trung tuan)) bang duong sinh toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (thien hach)) - hanh ((trung cua) OR (trung tuan)) bang duong sinh toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (thien hach)) - hanh ((trung cua) OR (trung tuan)) bang duong sinh toan cao*.