Perhaps you should try some spelling variations:
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sach ty)) nang ma hoi. hieu va pham duc va danh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang ma hoi. hieu va pham duc va danh vi cua tu*.