Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
cham luc » cham soc, nhan luc, cham cuu
va hanh » van hanh, va thanh, va danh
tieu su » thieu so
hieu su » hieu sau, hieu so, hieu suat
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
luc va » duc va, tuc va, loc va
vi cua » vai cua, di 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) or (su sach)) ky lang xa hoi. ((hieu su) OR (tieu su)) cham luc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ky lang xa hoi. ((hieu su) OR (tieu su)) cham luc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (su sach)) ky lang xa hoi. ((hieu su) OR (tieu su)) cham luc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ky lang xa hoi. ((hieu su) OR (tieu su)) cham luc va hanh vi cua tre*.