Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
vien cua » dien cua, tien cua, bien cua
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
xuc va » duc va, tuc va, luc va

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) or (toc sach)) ky tang ma hoa. hieu va cac xuc va thanh ((vien cua) OR (viec cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky tang ma hoa. hieu va cac xuc va thanh ((vien cua) OR (viec cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky tang ma hoa. hieu va cac xuc va thanh ((vien cua) OR (viec cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky tang ma hoa. hieu va cac xuc va thanh ((vien cua) OR (viec cua)) tre*.