Perhaps you should try some spelling variations:
nam trung » nam trong, tai trung, ba trung
nam truoc » nam thuoc, lam truoc, nam truc
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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 xa hoi. hieu van ((nam truoc) or (nam trung)) van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu van ((nam truoc) OR (nam trung)) van hanh vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu van ((nam truoc) or (nam trung)) van hanh vi cuu tre*.