Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
dau tren » dau tien, dat tren, dau tieng
mai hoi » dai hoi, lai hoi, mai doi
hieu ve » hieu va, hieu van
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
tu cam » tu cham, tu cac, tu nam
cam ky » cao ky, cac ky
ma hoi » xa hoi, ma hoa, me hoi
ve cam » ve cham, ve cac, va cam
tuc va » thuc va, truc va, tuc xa
vi dau » vi dai, va dau, bi dau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu cam ky nang ((ma hoi) OR (((mai hoi) OR (mai khoi)))). hieu ve cam tuc va hanh vi dau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cam ky nang ((ma hoi) or (((mai hoi) OR (mai khoi)))). hieu ve cam tuc va hanh vi dau tren~".
• Adding a wildcard symbol may retrieve word variants: tu cam ky nang ((ma hoi) or (((mai hoi) OR (mai khoi)))). hieu ve cam tuc va hanh vi dau tren*.