Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
cam hoc » cao hoc, am hoc, cam hoa
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
sach ty » sach y, sach tu, xach tay
hieu ve » hieu va, hieu van
dang xa » dang xay, lang xa, dang ha
ve cam » ve cham, ve cac, va cam

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 ty) OR (sach thu)) dang xa hoi. hieu ve cam hoc va dinh ((vai cuu) or (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) dang xa hoi. hieu ve cam hoc va dinh ((vai cuu) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach thu)) dang xa hoi. hieu ve cam hoc va dinh ((vai cuu) or (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach thu)) dang xa hoi. hieu ve cam hoc va dinh ((vai cuu) or (vai cua)) tre*.