Perhaps you should try some spelling variations:
sach ky » sach ty, sach kem, sach hay
cao hoc » co hoc, cho hoc, chat hoc
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, cuu tre, luy tre
sac ky » cac ky, sai ky
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((((sach ky) OR (sac ky))) or (sach y)) nang cao hoc. hieu va cac duc va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((((sach ky) OR (sac ky))) OR (sach y)) nang cao hoc. hieu va cac duc va hanh vi luu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((((sach ky) OR (sac ky))) or (sach y)) nang cao hoc. hieu va cac duc va hanh vi luu tre*".