Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
hieu van » hieu va, thien van, lieu va
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
duc ban » duc van, dua ban, duc man
benh vi » benh va, benh ve, benh li
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
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 (thuoc sach)) y nang xa hoi. hieu van cam ((duc ban) or (duc tan)) benh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) y nang xa hoi. hieu van cam ((duc ban) OR (duc tan)) benh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (thuoc sach)) y nang xa hoi. hieu van cam ((duc ban) or (duc tan)) benh vi cua tre*".