Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
xa khanh » xa thanh, van khanh, dat khanh
thi hanh » thi thanh
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
cac toi » cac thoi
hanh ca » hanh cac, hanh cat, hanh cua
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
ca hoi » cau hoi, cua hoi, xa hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach thi hanh ca hoi. hieu va ((cac tuc) or (cac toi)) xa khanh ((vai cua) OR (hai cua)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thi hanh ca hoi. hieu va ((cac tuc) OR (cac toi)) xa khanh ((vai cua) OR (hai cua)) viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thi hanh ca hoi. hieu va ((cac tuc) or (cac toi)) xa khanh ((vai cua) OR (hai cua)) viet".
• Adding a wildcard symbol may retrieve word variants: toc sach thi hanh ca hoi. hieu va ((cac tuc) or (cac toi)) xa khanh ((vai cua) OR (hai cua)) viet*.