Perhaps you should try some spelling variations:
sach vuc » sach duoc, sach nuoc, sach truc
vuc nang » cuc nang, vu nang, chuc nang
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
ma hoi » mai hoi, xa hoi, me hoi
va cam » va cham, va cac, va cao
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 vuc nang ((ma hoi) or (ma hoa)). hieu va cam luc van hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vuc nang ((ma hoi) OR (ma hoa)). hieu va cam luc van hanh vi su triet*.