Perhaps you should try some spelling variations:
ngoc duc » ngo duc, ngoc dung, ngoc de
su sach » vu sach
tinh te » kinh te, tinh tu, tinh he
va tinh » may tinh
ve ngoc » le ngoc, vu ngoc, ve nuoc
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua
so sach » so sanh, bo sach, co sach
te cua » tue cua, le cua, de cua
cua te » cua tu

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) or (so sach)) ky ((mang xa) or (lang xa)) hoi. hieu ve ngoc duc va tinh te cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ky ((mang xa) OR (lang xa)) hoi. hieu ve ngoc duc va tinh te cua te.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) ky ((mang xa) or (lang xa)) hoi. hieu ve ngoc duc va tinh te cua te*.