Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
su triet » su viet, su tien, ve triet
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty xang, ty hang
sach ty » sach y, sach tu, sach thu
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
ma hoi » xa hoi, ma hoa, me hoi
ve cam » ve cham, ve cac, va cam

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 ty nang ((ma hoi) OR (mai hoi)). hieu ve cam duc va hanh di ((cuu tre) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((ma hoi) OR (mai hoi)). hieu ve cam duc va hanh di ((cuu tre) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty nang ((ma hoi) OR (mai hoi)). hieu ve cam duc va hanh di ((cuu tre) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((ma hoi) OR (mai hoi)). hieu ve cam duc va hanh di ((cuu tre) or (su triet))*.