Perhaps you should try some spelling variations:
tinh van » trinh van, dinh van, tinh va
sach ty » sach tu, sach thu, xach tay
tang ma » mang may, tang van
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va tinh » may tinh
van cua » vang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ty) or (sach y)) ((tang ma) or (lang xa)) hoi. hieu va cac duc va tinh van cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sach y)) ((tang ma) OR (lang xa)) hoi. hieu va cac duc va tinh van cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) or (sach y)) ((tang ma) or (lang xa)) hoi. hieu va cac duc va tinh van cua tre*.