Perhaps you should try some spelling variations:
thanh gi » thanh nghi, thanh gian, thanh hai
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
la tren » loai tren, dua tren, dat tren
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
gi la » gi lam, gia la, gio la

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 ky ((dang xay) or (nang x)) hoi. hieu ve cham ((xuc va) OR (tuc va)) thanh gi la tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xay) OR (nang x)) hoi. hieu ve cham ((xuc va) OR (tuc va)) thanh gi la tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((dang xay) or (nang x)) hoi. hieu ve cham ((xuc va) OR (tuc va)) thanh gi la tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xay) or (nang x)) hoi. hieu ve cham ((xuc va) OR (tuc va)) thanh gi la tren*.