Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
xuc van » duc van, luc van, xuc ban
su viet » so viet
ve cam » ve cham, ve cac, va cam
vi su » va su, ve su, ki su

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 (lang xa)) hoi. hieu ve cam xuc van hanh vi su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cam xuc van hanh vi su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cam xuc van hanh vi su viet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky ((nang xa) OR (lang xa)) hoi. hieu ve cam xuc van hanh vi su viet*.