Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, mang may
van cac » van hac, van cau, van bac
xuc van » luc van, xuc ban, thuc van
duc van » duc va, duc tan, duc manh
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky ((nang ma) or (nang cao)) hoi. hieu van cac ((xuc van) or (duc van)) hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang ma) OR (nang cao)) hoi. hieu van cac ((xuc van) OR (duc van)) hanh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang ma) or (nang cao)) hoi. hieu van cac ((xuc van) or (duc van)) hanh vi cua tu*.