Perhaps you should try some spelling variations:
thang tai » hang tai, tang tai, thanh tai
van thang » van thanh, van khang, van hang
sach nay » sach hay, sach vay, sach nang
nay dang » nam dang, nao dang, nap dang
so sach » so sanh, bo sach, co sach
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
cuc te » cua te, cuc thue, cuc tieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach nay dang xa hoi. ((hieu va) or (hieu qua)) cac duc van thang tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach nay dang xa hoi. ((hieu va) OR (hieu qua)) cac duc van thang tai cuc te.
• Adding a wildcard symbol may retrieve word variants: so sach nay dang xa hoi. ((hieu va) or (hieu qua)) cac duc van thang tai cuc te*.