Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc day
vai cua » dai cua, hai cua, lai cua
vi cua » di cua
va am » va lam, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang xa hoi. hieu va am ((thuc va) or (thuc dan)) hanh ((vi cua) OR (vai cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang xa hoi. hieu va am ((thuc va) OR (thuc dan)) hanh ((vi cua) OR (vai cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang xa hoi. hieu va am ((thuc va) or (thuc dan)) hanh ((vi cua) OR (vai cua)) te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang xa hoi. hieu va am ((thuc va) or (thuc dan)) hanh ((vi cua) OR (vai cua)) te*.