Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
hai cua » thai cua, hoi cua, lai cua
ve cac » va cac, vien cac
cac bo » bac bo, cac co
bo va » bao va, do va, so va

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 xa hoi. hieu ve cac bo va hanh ((hai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ky nang xa hoi. hieu ve cac bo va hanh ((hai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) ky nang xa hoi. hieu ve cac bo va hanh ((hai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) OR (thuoc sach)) ky nang xa hoi. hieu ve cac bo va hanh ((hai cua) or (dai cua)) tre*.