Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
cau thuc » cau truc, cuu thuc, can thuc
van hanh » ban hanh, van anh, van ban
dieu tra » dieu tri, kiem tra, dieu cua
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
tra tre » tran tren, tran tri, tran tro
va cau » van cau, va cac, va dau

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: toc sach ky nang xa hoi. hieu va cau thuc ((van hanh) OR (van thanh)) dieu tra tre~.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu va cau thuc ((van hanh) or (van thanh)) dieu tra tre*.