Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
trung va » truong va, trang va, trung ha
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
van cac » van hac, van cau, van bac
doi cua » hoi cua

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