Perhaps you should try some spelling variations:
sach hay » sach han, sach ha, sach nay
dang xay » dang van, van xay
co sach » bo sach, cuon sach, hoc sach
thuc va » thuc vat, thuc dan, thuc day
phuc va » phuc vu, chuc va, thuc vat
hieu ve » hieu va, hieu van
lang xa » lang ha, lang van
ve cac » va cac, vien cac
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: co sach hay ((lang xa) OR (dang xay)) hoi. hieu ve cac ((phuc va) or (thuc va)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co sach hay ((lang xa) OR (dang xay)) hoi. hieu ve cac ((phuc va) OR (thuc va)) hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co sach hay ((lang xa) OR (dang xay)) hoi. hieu ve cac ((phuc va) or (thuc va)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: co sach hay ((lang xa) OR (dang xay)) hoi. hieu ve cac ((phuc va) or (thuc va)) hanh vi cua te*.