Perhaps you should try some spelling variations:
toan hanh » toan thanh, toan anh, tran hanh
thu sach » thuat sach, thuoc sach, thu hoach
duc toan » duc tan, duc ton, duc hoan
cao duc » dao duc, cao suc, giao duc
tu sach » su sach, te sach, tu cach
hieu ve » hieu va, hieu van
v nang » va nang, vu nang, van nang
ve cao » va cao, ve bao, ve cac
x hoi » xa hoi, o hoi, x ho
ki su » ky su
ve su » va 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 x hoi. hieu ve cao duc toan hanh ((ki su) or (ve su)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) v nang x hoi. hieu ve cao duc toan hanh ((ki su) OR (ve su)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) v nang x hoi. hieu ve cao duc toan hanh ((ki su) or (ve su)) triet*".