Perhaps you should try some spelling variations:
quan hai » quan ha, qua hai, quan tai
quan lai » quan li, quan tai, quan lap
su sach » so sach, vu sach
duc van » duc va, duc tan, duc manh
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
co sach » bo sach, cuon sach, hoc sach
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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 (co sach)) ky nang o hoi. hieu ve pham duc van ((quan lai) OR (quan hai)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (co sach)) ky nang o hoi. hieu ve pham duc van ((quan lai) OR (quan hai)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (co sach)) ky nang o hoi. hieu ve pham duc van ((quan lai) OR (quan hai)) cua te".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (co sach)) ky nang o hoi. hieu ve pham duc van ((quan lai) OR (quan hai)) cua te*.