Perhaps you should try some spelling variations:
dang hai » dang khai, hang hai, dung hai
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
ly hang » ly quang
ty hang » ty xang, thi hang, thu hang
hai cua » thai cua, dai cua, hoi cua
duc xa » duoc xa, duc va, duc ha

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 ((ty hang) or (ly hang)) mai hoi. hieu ve pham ((duc xa) OR (tuc xa)) dang hai cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty hang) OR (ly hang)) mai hoi. hieu ve pham ((duc xa) OR (tuc xa)) dang hai cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty hang) or (ly hang)) mai hoi. hieu ve pham ((duc xa) OR (tuc xa)) dang hai cua vat".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty hang) or (ly hang)) mai hoi. hieu ve pham ((duc xa) OR (tuc xa)) dang hai cua vat*.