Perhaps you should try some spelling variations:
gian cua » gian xu, ban cua
giau cua » gia cua, dieu cua, bieu cua
van canh » van anh, van hanh, van manh
tang van » dang van, hoang van, trong van
tu sach » thu sach, su sach, te sach
cac lop » cac hop, cac loai
lop van » lo van, long van, loai van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
tang ma » mang may

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 ((tang ma) or (tang van)) hoi. hieu va cac lop van canh ((giau cua) OR (gian cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((tang ma) OR (tang van)) hoi. hieu va cac lop van canh ((giau cua) OR (gian cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((tang ma) or (tang van)) hoi. hieu va cac lop van canh ((giau cua) OR (gian cua)) tre*".