Perhaps you should try some spelling variations:
ve triet » va trien, su triet
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
nang ma » tang ma, sang ma, nang cao
qua cao » qua cac, qua ca, qua cai
cao duc » dao duc, cao suc, giao duc
dao van » dang van
ma hoi » mai hoi, xa hoi, ma hoa
do van » so van

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 tu nang ma hoi. hieu qua cao duc va ((dao van) or (((do van) or (vo van)))) ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nang ma hoi. hieu qua cao duc va ((dao van) OR (((do van) OR (vo van)))) ve triet.
• Adding a wildcard symbol may retrieve word variants: tu sach tu nang ma hoi. hieu qua cao duc va ((dao van) or (((do van) or (vo van)))) ve triet*.