Perhaps you should try some spelling variations:
van nang » van quang, van ban, van dong
dan hanh » dang hanh, dan khanh, dan thanh
sach van » sach han, sach va, bach van
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
vi cua » vai cua, di cua
cua te » cua tu
va cam » va cham, va cac, va cao
de tai » de thi, te tai
ve tai » te tai, le tai, ve tac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach van nang xa hoi. hieu ((((ve tai) OR (de tai))) OR (va cam)) thuc dan hanh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach van nang xa hoi. hieu ((((ve tai) OR (de tai))) or (va cam)) thuc dan hanh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sach van nang xa hoi. hieu ((((ve tai) OR (de tai))) or (va cam)) thuc dan hanh vi cua te*.