Perhaps you should try some spelling variations:
luan hoan » luan van
hieu luan » hieu luat, hieu quan, tieu luan
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
duc van » duc tan, duc manh, duc phan
hanh ve » hanh vi, hanh va, hanh kem
su viet » so viet
x hoi » xa hoi, o hoi, x ho
ve su » va su

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 ty nang x hoi. hieu luan hoan ((duc van) or (duc va)) hanh ve su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu luan hoan ((duc van) OR (duc va)) hanh ve su viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu luan hoan ((duc van) or (duc va)) hanh ve su viet*.