Perhaps you should try some spelling variations:
thanh gian » thanh giang, thach giang, thanh san
sach thue » sach thieu, sach tham, cach thuc
hieu van » hieu va, thien van, lieu va
gian cua » gian xu, ban cua
sach thu » sach thieu, sach tham, cach thuc
va thanh » gia thanh, ban thanh, va tinh
cam hoc » cao hoc, am hoc, cam hoa
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
sach tu » cach tu, sach ty, sach uu
sang ma » tang ma, nang ma, sang tao
ma hoi » mai hoi, xa hoi, ma hoa

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