Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
vien cac » vien bach, vien dai, vien da
thanh do » thanh de, thanh pho, thanh hoa
dau tren » dau tien, dat tren, dau tieng
hang van » hoang van, hang va, dang van
van hoi » van hoa, van hoc, van hoe
duc gia » quoc gia
ve cau » ke cau, va cau, le cau
y hang » ly hang, ty hang, yu hang
do dau » doi dau, do dai, mo dau
ve cac » va cac

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 y hang van hoi. hieu ((ve cau) or (((ve cac) OR (vien cac)))) duc gia thanh do dau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y hang van hoi. hieu ((ve cau) OR (((ve cac) OR (vien cac)))) duc gia thanh do dau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y hang van hoi. hieu ((ve cau) or (((ve cac) OR (vien cac)))) duc gia thanh do dau tren".
• Adding a wildcard symbol may retrieve word variants: toc sach y hang van hoi. hieu ((ve cau) or (((ve cac) OR (vien cac)))) duc gia thanh do dau tren*.