Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc cao » thuoc cao, thuc co, thuc can
viec ban » viec lam, viec va, viec tai
viec dan » viec dang, viec dat, viec tang
cao dan » cao dang, cao danh, cac dan
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
y xang » ty xang
xang x » nang x
dan vi » doan vi, don vi, dan va
x hoi » xa hoi, o hoi, x ho

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 xang x hoi. nhieu ((viec dan) or (viec ban)) thuc cao dan vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y xang x hoi. nhieu ((viec dan) OR (viec ban)) thuc cao dan vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y xang x hoi. nhieu ((viec dan) or (viec ban)) thuc cao dan vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: toc sach y xang x hoi. nhieu ((viec dan) or (viec ban)) thuc cao dan vi ((cua tre) OR (cuu tre))*.