Perhaps you should try some spelling variations:
cac khoi » cac thoi, cac khoan, cach thoi
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
me hoi » le hoi
ve cam » ve cham, ve cac, va cam
cam tu » cam thu, nam tu, dam tu
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: so sach ky tang ((me hoi) or (((mai hoi) or (cac khoi)))). hieu ve cam tu va hanh vi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky tang ((me hoi) OR (((mai hoi) OR (cac khoi)))). hieu ve cam tu va hanh vi cua vat.
• Adding a wildcard symbol may retrieve word variants: so sach ky tang ((me hoi) or (((mai hoi) or (cac khoi)))). hieu ve cam tu va hanh vi cua vat*.