Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
luu truc » luu tru, cau truc, cuu thuc
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
hanh va » hang va, hanh vi
va luu » van luu, ta luu, vi luu

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 (su sach)) ky nang xa hoi. hieu ve ((cac nuoc) or (cam xuc)) van hanh va luu truc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (su sach)) ky nang xa hoi. hieu ve ((cac nuoc) OR (cam xuc)) van hanh va luu truc.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (su sach)) ky nang xa hoi. hieu ve ((cac nuoc) or (cam xuc)) van hanh va luu truc*.