Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
va chua » vua chua, va chu, a chua
ca chua » ca cua, sua chua
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
xuc va » tuc va, luc va, xac va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ky tang ma hoi. hieu ve cac ((xuc va) OR (duc va)) thanh ((va chua) or (ca chua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky tang ma hoi. hieu ve cac ((xuc va) OR (duc va)) thanh ((va chua) OR (ca chua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky tang ma hoi. hieu ve cac ((xuc va) OR (duc va)) thanh ((va chua) or (ca chua)) tre".
• Adding a wildcard symbol may retrieve word variants: thuat sach ky tang ma hoi. hieu ve cac ((xuc va) OR (duc va)) thanh ((va chua) or (ca chua)) tre*.