Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, dan cac
van bac » van ban, van bao, van hac
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 ty nang xa hoi. hieu ((van cac) OR (van bac)) duc va hanh vi cua cu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty nang xa hoi. hieu ((van cac) OR (van bac)) duc va hanh vi cua cu".
• Adding a wildcard symbol may retrieve word variants: doc sach ty nang xa hoi. hieu ((van cac) OR (van bac)) duc va hanh vi cua cu*.