Perhaps you should try some spelling variations:
trinh vi » trinh va, trinh ve, trinh viet
sach thu » sach thue, sach thieu, sach tham
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, xach tay
tang xa » trang xa, tang ma, lang xa
cua tre » cua te, cuu tre, cua triet
va coc » va cuoc, va cac, va hoc
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ty) OR (sach thu)) tang xa hoi. hieu va coc ((tuc va) or (duc va)) trinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ty) OR (sach thu)) tang xa hoi. hieu va coc ((tuc va) OR (duc va)) trinh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach thu)) tang xa hoi. hieu va coc ((tuc va) or (duc va)) trinh vi cua tre*".