Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
va chua » vua chua, ca chua, va chu
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
luc va » duc va, tuc va, loc va
va cua » via cua, ca cua, ma cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang xa hoi. hieu van cac ((luc va) or (thuc dan)) hanh ((va cua) OR (va chua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang xa hoi. hieu van cac ((luc va) OR (thuc dan)) hanh ((va cua) OR (va chua)) te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang xa hoi. hieu van cac ((luc va) or (thuc dan)) hanh ((va cua) OR (va chua)) te*".