Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cham xuc » cam xuc, chat xuc, pham duc
cua nuoc » cua quoc, cua nguoi, cua thuoc
doc sach » hoc sach, nuoc sach, dac sac
hieu va » lieu va, hieu qua
tai cua » thai cua, tai cuc, tri cua
ang xa » lang xa, mang xa, dang xay
ty ang » ty xang, ty hang, ty anh

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) OR (doc sach)) ty ang xa hoi. hieu va ((cham xuc) or (cham soc)) van hanh tai cua nuoc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ty ang xa hoi. hieu va ((cham xuc) OR (cham soc)) van hanh tai cua nuoc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ty ang xa hoi. hieu va ((cham xuc) or (cham soc)) van hanh tai cua nuoc".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) ty ang xa hoi. hieu va ((cham xuc) or (cham soc)) van hanh tai cua nuoc*.