Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
thu nang » thi nang, thu hang, thu bang
hieu van » hieu va, hieu ve
danh vai » danh sai, danh va, doanh van
sach thu » sach thue, sach thieu, sach tham
cam tuc » cam xuc, cam tu, nam thuc
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, tuc xa

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