Perhaps you should try some spelling variations:
thien van » thi van
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
va hang » van hang, va nang, va lang
tu sach » thu sach, su sach, te sach
nam luc » nang luc, nhan luc, nam duoc
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
di cu » di cau, di cua, da cu
di du » li du

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 ky dang xa hoi. thien van ((nam luc) or (nam thuc)) va hang ((di cu) OR (di du)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang xa hoi. thien van ((nam luc) OR (nam thuc)) va hang ((di cu) OR (di du)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang xa hoi. thien van ((nam luc) or (nam thuc)) va hang ((di cu) OR (di du)) tren".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang xa hoi. thien van ((nam luc) or (nam thuc)) va hang ((di cu) OR (di du)) tren*.