Perhaps you should try some spelling variations:
tuong hieu » thuong hieu, trong hieu, guong hieu
sach truc » cach thuc, sach tren, sach thu
truc thuc » truc thuoc, thuc thuc, truc thuy
dan tuong » ban tuong, dai tuong, dan trong
thuc thai » thuc pham, toc thai, thuc thuc
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
hoc dai » hoc dan

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