Perhaps you should try some spelling variations:
van thanh » ban thanh
thu sach » tu sach, thuat sach, thuoc sach
van tuan » van quan, van ban, anh tuan
su tien » su kien, su hien, tu tieng
sach vu » sach va, sach tu, sach uu
vu nang » vuc nang, va nang, vu dang
va cam » va cham, va cao, va cai
x hoi » xa hoi, o hoi, x ho
ve su » va su

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach vu nang x hoi. hieu ((va cam) or (va cac)) vuc ((van thanh) OR (van tuan)) ve su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach vu nang x hoi. hieu ((va cam) OR (va cac)) vuc ((van thanh) OR (van tuan)) ve su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach vu nang x hoi. hieu ((va cam) or (va cac)) vuc ((van thanh) OR (van tuan)) ve su tien".
• Adding a wildcard symbol may retrieve word variants: thu sach vu nang x hoi. hieu ((va cam) or (va cac)) vuc ((van thanh) OR (van tuan)) ve su tien*.