Perhaps you should try some spelling variations:
nhat hanh » nhat ban, nhat minh
vat thanh » dat thanh, gat thanh, tat thanh
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
vat hanh » van hanh, va hanh, dat khanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu
x hoi » xa hoi, o hoi, x ho

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 hoi. hieu van nam thuc ((((vat hanh) OR (nhat hanh))) or (vat thanh)) vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu van nam thuc ((((vat hanh) OR (nhat hanh))) OR (vat thanh)) vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu van nam thuc ((((vat hanh) OR (nhat hanh))) or (vat thanh)) vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van nam thuc ((((vat hanh) OR (nhat hanh))) or (vat thanh)) vi cuu tre*.