Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
thong cong » trong cong, tong cong, thong thong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap
mang he » mang ke, mang se, nang he
bang he » bang khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc thieu sach - hanh ((mang he) OR (bang he)) thong cong tac toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc thieu sach - hanh ((mang he) OR (bang he)) thong cong tac toan cau".
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - hanh ((mang he) OR (bang he)) thong cong tac toan cau*.