Perhaps you should try some spelling variations:
doc sach » toc sach, nuoc sach, dac sac
hieu van » hieu va, thien van, lieu va
hoc sach » hoc sinh, hoc cac, hoc anh
giao su » giao duc
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
su tien » su kien, su hien, tu tieng

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) or (hoc sach)) ty nang xa hoi. hieu van cam xuc ((va danh) or (va dinh)) giao su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (hoc sach)) ty nang xa hoi. hieu van cam xuc ((va danh) OR (va dinh)) giao su tien.
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (hoc sach)) ty nang xa hoi. hieu van cam xuc ((va danh) or (va dinh)) giao su tien*.