Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
va hanh » van hanh, va thanh, va danh
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va
vi cua » vai cua, di cua

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 y ((((nang ma) or (nang x))) or (van xay)) hoi. hieu ve cac luc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((((nang ma) OR (nang x))) OR (van xay)) hoi. hieu ve cac luc va hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((((nang ma) or (nang x))) or (van xay)) hoi. hieu ve cac luc va hanh vi cua viet*.