Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
hanh dao » lanh dao, thanh dat, thanh dam
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
dao cua » dai cua, day cua, dan cua
va hanh » van hanh, va thanh, va danh
lam tuc » lam thuoc, lam truoc, luat tuc
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
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) or (thuoc sach)) ty nang xa hoi. ((hieu van) OR (hieu va)) lam tuc va hanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) ty nang xa hoi. ((hieu van) OR (hieu va)) lam tuc va hanh dao cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuoc sach)) ty nang xa hoi. ((hieu van) OR (hieu va)) lam tuc va hanh dao cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuoc sach)) ty nang xa hoi. ((hieu van) OR (hieu va)) lam tuc va hanh dao cua tre*.