Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi hanh » thi thanh
hieu van » hieu va, thien van, lieu va
cam thuc » am thuc, nam thuc, cam thu
va danh » va dinh, va dan, dia danh
tu sach » thu sach, su sach, te sach
van cam » van nam, van lam, van cau
hanh xa » hanh va, hanh ma, hanh xu
va hanh » van hanh, va thanh, ban hanh
lam va » nam va, dam va, am va
lam ha » nam ha, dam ha, lam chat

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 thi hanh xa hoi. hieu van cam thuc ((va hanh) OR (va danh)) ((lam va) or (lam ha)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thi hanh xa hoi. hieu van cam thuc ((va hanh) OR (va danh)) ((lam va) OR (lam ha)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach thi hanh xa hoi. hieu van cam thuc ((va hanh) OR (va danh)) ((lam va) or (lam ha)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach thi hanh xa hoi. hieu van cam thuc ((va hanh) OR (va danh)) ((lam va) or (lam ha)) triet*.