Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, nhung don
hang cong » dang cong, hang nong, bang cong
trinh va » trinh van, trinh vat, trinh ve
tap toan » tap doan, tap quan, bai toan
toan ban » van ban

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 trinh va ((nhung cong) OR (hang cong)) tap toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc thieu sach - hanh trinh va ((nhung cong) OR (hang cong)) tap toan ban".
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - hanh trinh va ((nhung cong) OR (hang cong)) tap toan ban*.