Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cua triet » cua viet, su triet, va triet
duc manh » suc manh, duc anh, duc minh
va nang » van nang, da nang, cam nang
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
v nang » vu nang, van nang, voi nang
vi cua » vai cua, di cua
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((v nang) OR (va nang)) xa hoi. hieu va co ((xuc van) or (duc manh)) hanh vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((v nang) OR (va nang)) xa hoi. hieu va co ((xuc van) OR (duc manh)) hanh vi cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((v nang) OR (va nang)) xa hoi. hieu va co ((xuc van) or (duc manh)) hanh vi cua triet".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((v nang) OR (va nang)) xa hoi. hieu va co ((xuc van) or (duc manh)) hanh vi cua triet*.