Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thu sach » thuat sach, thuoc sach, thu hoach
luu van » cuu van, luan van, luu hanh
luc van » luoc van, duc van, luc va
tu sach » su sach, te sach, tu cach
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
ve cam » ve cham, ve cac, va cam
v nang » va nang, vu nang, van nang
vi su » va su, ve su, ki 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) or (thu sach)) v nang xa hoi. hieu ve cam ((luc van) OR (luu van)) hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) v nang xa hoi. hieu ve cam ((luc van) OR (luu van)) hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) v nang xa hoi. hieu ve cam ((luc van) OR (luu van)) hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) v nang xa hoi. hieu ve cam ((luc van) OR (luu van)) hanh vi su triet*.