Perhaps you should try some spelling variations:
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
hieu ve » hieu van
sang ma » tang ma, nang ma, sang tao
ma hoi » mai hoi, xa hoi, ma hoa
sac ky » cac ky, sai ky
va cua » va chua, via cua, ca cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) OR (sac ky)) sang ma hoi. ((hieu ve) or (hieu va)) cam duc va hanh va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) sang ma hoi. ((hieu ve) OR (hieu va)) cam duc va hanh va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) sang ma hoi. ((hieu ve) or (hieu va)) cam duc va hanh va cua te".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) sang ma hoi. ((hieu ve) or (hieu va)) cam duc va hanh va cua te*.