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
duc gia » quoc gia
ve cau » ke cau, va cau, le cau
y hang » ly hang, ty hang, yu hang
va hoi » xa hoi, va hoc, va hoa
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 va 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 va 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 va hoi. hieu ((ve cau) or (((ve cac) or (vien cac)))) duc gia thanh do dau tren*.