Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thong cong » trong cong, tong cong, thong thong
hoc thieu » toc thieu, hoc hien
csinh cua » chinh cua, tinh cua, trinh cua
sinh cua » manh cua, dinh cuu, sinh va
tam toan » tam than, pham toan, tam thanh
tap toan » tap doan, tap quan, bai toan

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 - hanh ((csinh cua) or (sinh cua)) thong cong ((tam toan) or (tap toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - hanh ((csinh cua) OR (sinh cua)) thong cong ((tam toan) OR (tap toan)) ban.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh ((csinh cua) or (sinh cua)) thong cong ((tam toan) or (tap toan)) ban*.