Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
anh xquang » anh quan, anh xuan
hoc thieu » toc thieu, hoc hien
anh quang » anh quan, nhanh quang, tinh quang
mach toan » manh toan, hach toan, hoach toan
mach tuan » manh tuan, mach tiang, anh tuan
duc dung » duc hung, duc cuong, duc trung

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 - ((anh quang) or (anh xquang)) duc dung trong ((mach toan) OR (mach tuan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - ((anh quang) OR (anh xquang)) duc dung trong ((mach toan) OR (mach tuan)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - ((anh quang) or (anh xquang)) duc dung trong ((mach toan) OR (mach tuan)) tap".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - ((anh quang) or (anh xquang)) duc dung trong ((mach toan) OR (mach tuan)) tap*.