Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
toc sach » hoc sach, doc sach, thuoc sach
vien cac » vien bach, vien dai, vien da
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
cac ban » cac dan, cac van, can ban
va danh » va dan, va hanh, dia danh
va dinh » van dinh, va kinh, va tinh
vi su » va su, ve su, ki su
kien » bien, tien, dien

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 ky lang xa hoi. hieu vien cac ban ((va danh) or (va dinh)) vi su kien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu vien cac ban ((va danh) OR (va dinh)) vi su kien.
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu vien cac ban ((va danh) or (va dinh)) vi su kien*.