Perhaps you should try some spelling variations:
sach nay » sach vay, sach nang, sach ngan
hieu van » hieu va, thien van, lieu va
sach hay » sach han, sach ha, sach vay
thuc va » thuc vat, thuc dan, thuc day
phuc va » phuc vu, chuc va, thuc vat
van cau » van dau, van hau, van chat
lang xa » lang ha, dang xay, lang van
vi cua » vai cua, di cua
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: so ((sach hay) OR (sach nay)) lang xa hoi. hieu van cau ((phuc va) or (thuc va)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach hay) OR (sach nay)) lang xa hoi. hieu van cau ((phuc va) OR (thuc va)) hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach hay) OR (sach nay)) lang xa hoi. hieu van cau ((phuc va) or (thuc va)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: so ((sach hay) OR (sach nay)) lang xa hoi. hieu van cau ((phuc va) or (thuc va)) hanh vi cua te*.