Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
ly hoang » le hoang, ly hong, ly hoan
ly hang » ly quang
hieu va » lieu va, hieu qua
va dinh » van dinh, va kinh, vu dinh
va tinh » may tinh
vi cua » vai cua, di cua
va cam » va cham, va cac, va cao

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 ((ly hoang) or (ly hang)) xa hoi. hieu va cam xuc ((va dinh) OR (va tinh)) vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ly hoang) OR (ly hang)) xa hoi. hieu va cam xuc ((va dinh) OR (va tinh)) vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ly hoang) or (ly hang)) xa hoi. hieu va cam xuc ((va dinh) OR (va tinh)) vi cua viet".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ly hoang) or (ly hang)) xa hoi. hieu va cam xuc ((va dinh) OR (va tinh)) vi cua viet*.