Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
xuc van » duc van, luc van, xuc ban
van cam » van nam, van lam, van cau
sang ma » tang ma, nang ma, sang tao
nang xa » nang x, lang xa, nang ma
su viet » so viet

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