Perhaps you should try some spelling variations:
hien bach » vien bach, thien hach, hien hanh
bach duoc » bach tuoc, sach duoc, ban duoc
hieu hien » bieu hien, dieu hien, chieu chien
toc sach » hoc sach, doc sach, thuoc sach
chu tre » chu tri, cuu tre, cau tren
va hang » van hang, va nang, va lang
duoc va » nuoc va, duc va, duoc ma
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
cho tre » cho thue, khoe tre

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 (toc sach)) ky nang xa hoi. hieu hien bach duoc va hang va ((chu tre) OR (cho tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky nang xa hoi. hieu hien bach duoc va hang va ((chu tre) OR (cho tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky nang xa hoi. hieu hien bach duoc va hang va ((chu tre) OR (cho tre))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky nang xa hoi. hieu hien bach duoc va hang va ((chu tre) OR (cho tre))*.