Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu dung » thuy dung, thuc dung, thu dang
hieu van » hieu va, thien van, lieu va
te sach » toc sach
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
dung y » dung _, dung may, dung tay
va cuu » va chu, va huu
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thu dung y thai. hieu van nam ((xuc va) or (tuc va)) tinh ((va cuu) OR (va cau)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thu dung y thai. hieu van nam ((xuc va) OR (tuc va)) tinh ((va cuu) OR (va cau)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thu dung y thai. hieu van nam ((xuc va) or (tuc va)) tinh ((va cuu) OR (va cau)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach thu dung y thai. hieu van nam ((xuc va) or (tuc va)) tinh ((va cuu) OR (va cau)) tre*.