Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hanh di » hanh de, hang di, danh di
xuc van » duc van, luc van, vuc van
hoc sac » hoc sach, hoc cac, hoc mac
ve chat » va chat, van chat
nang ma » tang ma, sang ma, nang cao
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac

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

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