Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
sach kha » sach nha, sach ha, sach tham
kha nang » phap nang, ky nang, ki nang
nam thuc » nam thuoc, am thuc, nam thu
cam thuc » am thuc, cam thu, can thuc
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
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: su sach kha nang xa hoi. ((hieu ve) OR (hieu va)) ((cam thuc) or (nam thuc)) va hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach kha nang xa hoi. ((hieu ve) OR (hieu va)) ((cam thuc) OR (nam thuc)) va hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach kha nang xa hoi. ((hieu ve) OR (hieu va)) ((cam thuc) or (nam thuc)) va hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: su sach kha nang xa hoi. ((hieu ve) OR (hieu va)) ((cam thuc) or (nam thuc)) va hanh vi su triet*.