Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
va triet » va thiet, va trien, ve triet
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
ma hoi » mai hoi, xa hoi, ma hoa
va cao » va cac, va co, va dao
xuc va » duc va, tuc va, xac va
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va, loc va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach y nang ma hoi. hieu va cao ((xuc va) OR (luc va)) hanh vi ((cua te) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach y nang ma hoi. hieu va cao ((xuc va) OR (luc va)) hanh vi ((cua te) OR (va triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach y nang ma hoi. hieu va cao ((xuc va) OR (luc va)) hanh vi ((cua te) or (va triet))*".