Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
quoc ban » quoc bao, quoc lan, quoc quan
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
duc ban » duc tan, duc van, dua ban
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: tu sach ky ((nang x) or (nang ma)) hoi. hieu van cau ((quoc ban) or (duc ban)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang x) OR (nang ma)) hoi. hieu van cau ((quoc ban) OR (duc ban)) hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang x) or (nang ma)) hoi. hieu van cau ((quoc ban) or (duc ban)) hanh vi cua te*.