Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
xuc van » duc van, luc van, vuc van
ty nang » ky nang, ty hang, ly nang
hanh di » hanh vi, hanh de, hang di
va cham » va chat, va tham
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ((ty nang) OR (ty xang)) ma hoi. hieu ((va cham) or (ve cac)) xuc van hanh di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((ty nang) OR (ty xang)) ma hoi. hieu ((va cham) OR (ve cac)) xuc van hanh di cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((ty nang) OR (ty xang)) ma hoi. hieu ((va cham) or (ve cac)) xuc van hanh di cua viet".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((ty nang) OR (ty xang)) ma hoi. hieu ((va cham) or (ve cac)) xuc van hanh di cua viet*.