Perhaps you should try some spelling variations:
dieu cua » dieu tra
thu sac » thu sach, thu san, thu xac
nang xa » nang x, lang xa, nang ma
hieu de » hieu ve, hieu he, hieu le
duoc va » duc va, duoc ma, duong va
sac ky » cac ky, sai ky
de tao » de dao, de tai, de tro
de cua » le cua, te cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky nang xa hoi. hieu de tao ((duoc va) or (nuoc va)) danh ((de cua) OR (dieu cua)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang xa hoi. hieu de tao ((duoc va) OR (nuoc va)) danh ((de cua) OR (dieu cua)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang xa hoi. hieu de tao ((duoc va) or (nuoc va)) danh ((de cua) OR (dieu cua)) tu".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang xa hoi. hieu de tao ((duoc va) or (nuoc va)) danh ((de cua) OR (dieu cua)) tu*.