Perhaps you should try some spelling variations:
ve triet » va trien, su triet
sang tao » hang tai
va thanh » gia thanh, ban thanh, le thanh
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
va tinh » may tinh
su sach » so sach, vu sach
vi ve » va ve, gi ve, ve ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu ((nang ma) or (sang tao)) hoi. hieu van cau duc ((va thanh) or (va tinh)) vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang ma) OR (sang tao)) hoi. hieu van cau duc ((va thanh) OR (va tinh)) vi ve triet.
• Adding a wildcard symbol may retrieve word variants: su sach thu ((nang ma) or (sang tao)) hoi. hieu van cau duc ((va thanh) or (va tinh)) vi ve triet*.