Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cac thuc » cach thuc, cac thu, can thuc
ve triet » va trien, su triet
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky sang » ky nang, ky tang, duy sang
ma hoi » mai hoi, xa hoi, ma hoa
ve cac » va cac, vien cac

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 sang) or (ky dang)) ma hoi. hieu ve cac thuc van hanh vi ((cua viet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky sang) OR (ky dang)) ma hoi. hieu ve cac thuc van hanh vi ((cua viet) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky sang) or (ky dang)) ma hoi. hieu ve cac thuc van hanh vi ((cua viet) or (ve triet))*.