Perhaps you should try some spelling variations:
doc sach » hoc sach, nuoc sach, dac sac
toc sach » hoc sach, thuoc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
vi cua » vai cua, di cua
cua cu » cua chu, cua cau, cua su

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 (toc sach)) ty nang xa hoi. hieu van cac duc va hanh vi cua cu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (toc sach)) ty nang xa hoi. hieu van cac duc va hanh vi cua cu".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) OR (toc sach)) ty nang xa hoi. hieu van cac duc va hanh vi cua cu*.