Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
bien cac » vien cac, dien cac, bien ca
nien cac » vien cac, dien cac, hien cac
cua viet » ca viet, hoa viet, cua vat
thu sach » thuat sach, thuoc sach, thu hoach
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
xuc van » duc van, luc van, vuc van
tu sach » su sach, te sach, tu cach
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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 (thu sach)) ky sang ma hoi. thieu ((nien cac) or (bien cac)) xuc van hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky sang ma hoi. thieu ((nien cac) OR (bien cac)) xuc van hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky sang ma hoi. thieu ((nien cac) or (bien cac)) xuc van hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky sang ma hoi. thieu ((nien cac) or (bien cac)) xuc van hanh vi cua viet*.