Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ca » hieu cac, hieu cua, hieu va
luc van » luoc van, duc van, luc va
luu van » cuu van, luan van, luu hanh
ca viet » va viet, co viet, hoa viet

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 ky nang xa hoi. hieu ca nhan ((luc van) OR (luu van)) hanh vi ((cua triet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu ca nhan ((luc van) OR (luu van)) hanh vi ((cua triet) OR (ca viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ca nhan ((luc van) OR (luu van)) hanh vi ((cua triet) or (ca viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ca nhan ((luc van) OR (luu van)) hanh vi ((cua triet) or (ca viet))*.