Perhaps you should try some spelling variations:
danh thanh » dinh thanh, dang thanh, nhanh thanh
thanh lam » thanh lap, hanh lam, thanh nam
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
pham duy » pham duc
duy danh » duy anh, duy ranh, day danh
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
ca viet » va viet, co viet, hoa viet
lam ca » lam cua, lam cha, lam co
x hoi » xa hoi, o hoi, 5 hoi

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) or (x ho)). hieu van pham duy danh thanh lam ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (x ho)). hieu van pham duy danh thanh lam ca viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) or (x ho)). hieu van pham duy danh thanh lam ca viet*.