Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
tat thanh » tai thanh, ta thanh, tat thang
hieu van » hieu va, thien van, lieu va
vat hanh » vat thanh, van hanh, nhat hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
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 thuoc ((((vat hanh) or (va hanh))) or (tat 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 thuoc ((((vat hanh) OR (va hanh))) OR (tat thanh)) vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van nam thuoc ((((vat hanh) or (va hanh))) or (tat thanh)) vi cuu tre*.