Perhaps you should try some spelling variations:
van thiet » dan thiet, can thiet, van thien
cham xuc » cam xuc, chat xuc, cham soc
dang mai » dang hai, dang mau, dang bai
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va cham » va chat, va tham
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
ky dang » ky nang, ky danh

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 ky dang mai hoi. hieu va cham xuc ((va hanh) or (va danh)) vi ((van thiet) OR (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky dang mai hoi. hieu va cham xuc ((va hanh) OR (va danh)) vi ((van thiet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky dang mai hoi. hieu va cham xuc ((va hanh) or (va danh)) vi ((van thiet) OR (va thiet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky dang mai hoi. hieu va cham xuc ((va hanh) or (va danh)) vi ((van thiet) OR (va thiet))*.