Perhaps you should try some spelling variations:
sach ky » sac ky, sach kem, sach hay
sach ty » sach tu, sach thu, xach tay
cao hoi » cau hoi, co hoi, cao hoc
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, cuu tre, luy tre
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va
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: doc ((((sach ky) OR (sach ty))) or (sach y)) nang cao hoi. hieu ve cam xuc va hanh vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((((sach ky) OR (sach ty))) OR (sach y)) nang cao hoi. hieu ve cam xuc va hanh vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((((sach ky) OR (sach ty))) or (sach y)) nang cao hoi. hieu ve cam xuc va hanh vi luu tre".
• Adding a wildcard symbol may retrieve word variants: doc ((((sach ky) OR (sach ty))) or (sach y)) nang cao hoi. hieu ve cam xuc va hanh vi luu tre*.