Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thu sac » thu san, thu xac, thu dac
hieu va » lieu va, hieu qua
cac lao » ca lao, cac loai, cac giao
va hanh » van hanh, va thanh, va danh
hai cua » thai cua, dai cua, lai cua
hoi cua » hoi chuc
lao va » tao va, cao va, bao va
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 sac) or (thu sach)) ky nang x hoi. hieu va cac lao va hanh ((hai cua) OR (hoi cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sac) OR (thu sach)) ky nang x hoi. hieu va cac lao va hanh ((hai cua) OR (hoi cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sac) or (thu sach)) ky nang x hoi. hieu va cac lao va hanh ((hai cua) OR (hoi cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sac) or (thu sach)) ky nang x hoi. hieu va cac lao va hanh ((hai cua) OR (hoi cua)) tre*.