Perhaps you should try some spelling variations:
sach thi » sach thu, sach tai, sach thieu
thi nang » thi cong, ki nang, thi hanh
cham loc » chon loc, cham o, hau loc
te sach » toc sach
va hanh » van hanh, va thanh, va danh
hai cua » thai cua, dai cua, hoi cua
lai cua » dai cua, lai chau, thai cua
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thi nang x hoi. hieu qua ((cham loc) OR (cham soc)) va hanh ((hai cua) or (lai cua)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thi nang x hoi. hieu qua ((cham loc) OR (cham soc)) va hanh ((hai cua) OR (lai cua)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thi nang x hoi. hieu qua ((cham loc) OR (cham soc)) va hanh ((hai cua) or (lai cua)) tu".
• Adding a wildcard symbol may retrieve word variants: te sach thi nang x hoi. hieu qua ((cham loc) OR (cham soc)) va hanh ((hai cua) or (lai cua)) tu*.