Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
thuat san » thuat toan, thuat song, thuat lanh
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
duc van » duc tan, duc manh, duc phan
ve cam » ve cham, ve cac, va cam
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: ((tu sach) or (thuat san)) ky nang cao hoi. hieu ve cam ((duc van) OR (duc va)) thanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat san)) ky nang cao hoi. hieu ve cam ((duc van) OR (duc va)) thanh dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thuat san)) ky nang cao hoi. hieu ve cam ((duc van) OR (duc va)) thanh dai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat san)) ky nang cao hoi. hieu ve cam ((duc van) OR (duc va)) thanh dai cua te*.