Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien, ve triet
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
va danh » va dinh, va dan, va hanh
cau tu » dau tu, cau truc
ki su » ky su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang x ho. hieu van cau tu ((va thanh) or (va danh)) ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang x ho. hieu van cau tu ((va thanh) OR (va danh)) ki su triet.
• Adding a wildcard symbol may retrieve word variants: so sach ky nang x ho. hieu van cau tu ((va thanh) or (va danh)) ki su triet*.