Perhaps you should try some spelling variations:
dan thanh » dang thanh, danh thanh, ban thanh
thanh va » thanh van, hanh va, thanh ha
thuc dan » thuc hanh, hoc dan, thuc vat
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cua triet, dua tren
su sach » so sach, vu sach
va pham » van pham, va phap, va phan
ty hang » ly hang, ty xang, thi hang
cuu tre » cau tren, cau treo
va hoi » xa hoi, va hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty hang va hoi. hieu ((va pham) or (va phat)) thuc dan thanh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty hang va hoi. hieu ((va pham) OR (va phat)) thuc dan thanh va ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty hang va hoi. hieu ((va pham) or (va phat)) thuc dan thanh va ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ty hang va hoi. hieu ((va pham) or (va phat)) thuc dan thanh va ((cua tre) OR (cuu tre))*.