Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
hieu van » hieu va, thien van, lieu va
thai cua » than cua, tai cuc, tri cua
te sach » toc sach
xa hanh » xa thanh, xa khanh, va hanh
hau tuc » hieu tuc, thai tuc
mang xa » lang xa, mang may, dang xay
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet

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