Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
hanh tai » thanh tai, hang tai, han tai
doc sach » hoc sach, nuoc sach, dac sac
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
hieu va » lieu va, hieu qua
ky dang » ky nang, ky danh
dang ha » dong ha, dung ha, lang ha
ha hoi » hoa hoi, ha noi, xa hoi
cuc te » cua te, cuc thue, cuc tieu

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)) ky dang ha hoi. hieu va ((cam xuc) or (nam thuc)) van hanh tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky dang ha hoi. hieu va ((cam xuc) OR (nam thuc)) van hanh tai cuc te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky dang ha hoi. hieu va ((cam xuc) or (nam thuc)) van hanh tai cuc te*.