Perhaps you should try some spelling variations:
dieu tra » dieu tri, kiem tra, dieu cua
tu sach » thu sach, te sach, tu cach
ho ngoc » do ngoc, ho nuoc, lo ngoc
nang xa » nang x, lang xa, nang ma
su sach » so sach, vu sach
tra tre » tran tren, tran tri, tran tro
va dap » va dao, va dau
ca dan » cac dan, ca dao
va ho » va hoc, va hoa, va hoi

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 (su sach)) ky nang xa hoi. lieu va ho ngoc ((va dap) or (ca dan)) dieu tra tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang xa hoi. lieu va ho ngoc ((va dap) OR (ca dan)) dieu tra tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang xa hoi. lieu va ho ngoc ((va dap) or (ca dan)) dieu tra tre*".