Perhaps you should try some spelling variations:
luan phan » luan hoan
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
va hanh » van hanh, va thanh, va danh
hanh ki » hanh vi, hanh ky, hanh kien
su viet » so viet
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: tu sach ty nang xa hoi. hieu ((luan phan) or (luan van)) duc va hanh ki su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang xa hoi. hieu ((luan phan) OR (luan van)) duc va hanh ki su viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu ((luan phan) or (luan van)) duc va hanh ki su viet*.