Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
cau duc » cao duc, cau luc, chu duc
duc van » duc va, duc tan, duc manh
va cau » van cau, va cac, va dau
vi cua » vai cua, di cua
cua te » cua tu

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

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