Perhaps you should try some spelling variations:
thanh lai » thanh hai, thanh lap, thanh loi
van thanh » ban thanh, van tuan
tu sach » thu sach, su sach, te sach
vu sach » su sach, vu khach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
chau te » chau tho
nang o » nang co, nang ho, nang ro
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: ((tu sach) or (((vu sach) OR (vu bach)))) ky nang o hoi. hieu va cac duc van thanh lai chau te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (((vu sach) OR (vu bach)))) ky nang o hoi. hieu va cac duc van thanh lai chau te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (((vu sach) OR (vu bach)))) ky nang o hoi. hieu va cac duc van thanh lai chau te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (((vu sach) OR (vu bach)))) ky nang o hoi. hieu va cac duc van thanh lai chau te*.