Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
than cua » nhan cua, ban cua, gian cua
dang xay » dang van, van xay
thai cua » tai cuc, tri cua, dai cua
cam tuc » cam xuc, cam tu, nam thuc
xa hanh » xa thanh, xa khanh, va hanh
tu sach » thu sach, su sach, te sach
van cam » van nam, van lam, van cau
sach ky » sac ky, sach y, sach ty

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 ((dang xay) or (nang x)) hoi. hieu van cam tuc xa hanh ((thai cua) OR (than cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xay) OR (nang x)) hoi. hieu van cam tuc xa hanh ((thai cua) OR (than cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((dang xay) or (nang x)) hoi. hieu van cam tuc xa hanh ((thai cua) OR (than cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xay) or (nang x)) hoi. hieu van cam tuc xa hanh ((thai cua) OR (than cua)) tre*.