Perhaps you should try some spelling variations:
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
va danh » va dinh, va dan, va hanh
vi cua » vai cua
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, x ho

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

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