Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
ty nang » ty xang, ty hang, ly nang
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
va bac » van bac, va cac, va bai
xuc va » tuc va, luc va, xac va
va cua » va chua, via cua, ca cua
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: thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va bac ((xuc va) or (duc va)) hanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va bac ((xuc va) OR (duc va)) hanh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va bac ((xuc va) or (duc va)) hanh va cua te".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ty nang) OR (ky nang)) xa hoi. hieu va bac ((xuc va) or (duc va)) hanh va cua te*.