Perhaps you should try some spelling variations:
vien sach » dien sach, viet sach, kien sach
ban hanh » ban hang
va danh » va dinh, va dan, va hanh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang xa hoi. hieu ((vien sach) OR (vien bach)) nuoc ((ban hanh) or (va danh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. hieu ((vien sach) OR (vien bach)) nuoc ((ban hanh) OR (va danh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. hieu ((vien sach) OR (vien bach)) nuoc ((ban hanh) or (va danh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. hieu ((vien sach) OR (vien bach)) nuoc ((ban hanh) or (va danh)) di cua tre*.