Perhaps you should try some spelling variations:
tuong hieu » thuong hieu, trong hieu, guong hieu
sach truc » cach thuc, sach tren, sach thue
dai tuong » dai cuong, doi tuong, dai duong
thuc thai » thuc pham, toc thai
thuc thuc » hoc thuc
sach thu » sach thue, sach thieu, sach tham
thuc dai » thuc dan, thuc day, thuc tai
hoc giai » hoc giao, hoc dai, so giai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach truc) or (sach thu)) thuc dai tuong hieu ((((thuc thai) or (thuc thuc))) or (hoc giai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach truc) OR (sach thu)) thuc dai tuong hieu ((((thuc thai) OR (thuc thuc))) OR (hoc giai)).
• Adding a wildcard symbol may retrieve word variants: tu ((sach truc) or (sach thu)) thuc dai tuong hieu ((((thuc thai) or (thuc thuc))) or (hoc giai))*.