Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
phan luc » nhan luc, phan duc, phan suc
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
hieu va » lieu va, hieu qua
luc van » luoc van, luu van, duc van
va phan » van phan, va phat, va phap
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) OR (thuoc sach)) ky nang x hoi. hieu va phan luc van hanh vi ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang x hoi. hieu va phan luc van hanh vi ((va triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) ky nang x hoi. hieu va phan luc van hanh vi ((va triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) ky nang x hoi. hieu va phan luc van hanh vi ((va triet) or (su triet))*.