Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hoc anh » hoc nganh, hoc nhanh, ngoc anh
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc dan, thuc day
va dau » va dao
di cua » dai cua, doi cua, de cua
va cau » van cau, va cac, va cao
v nang » va nang, vu nang, van nang
cua te » cua tu

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

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