Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
va bac » van bac, va cac, va bai
bac vo » bac bo, bac ho, bac va
x hoi » xa hoi, o hoi, x ho
vi su » ve su, ki su, oi su

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 bac vo van hanh ((vi su) or (va 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 bac vo van hanh ((vi su) OR (va 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 bac vo van hanh ((vi su) or (va su)) triet".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) ky nang x hoi. hieu va bac vo van hanh ((vi su) or (va su)) triet*.