Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
va trinh » van trinh, va tinh, lap trinh
tu sach » thu sach, su sach, te sach
thi van » thi lan, thi hanh, thi nang
vi cua » vai cua
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho
nuoc » quoc, duoc, ngoc

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 thu nang x hoi. ((thien van) or (thi van)) dat nuoc va trinh ((vi cua) OR (di cua)) tuc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu nang x hoi. ((thien van) OR (thi van)) dat nuoc va trinh ((vi cua) OR (di cua)) tuc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thu nang x hoi. ((thien van) or (thi van)) dat nuoc va trinh ((vi cua) OR (di cua)) tuc".
• Adding a wildcard symbol may retrieve word variants: tu sach thu nang x hoi. ((thien van) or (thi van)) dat nuoc va trinh ((vi cua) OR (di cua)) tuc*.