Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
sach ky » sac ky, sach y, sach ty
vai cua » hai cua, lai cua, bai cua
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cau luc » cau truc, cau phuc
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
va cau » van cau, va cac, va dau

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

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