Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
hieu van » hieu va, thien van, lieu va
tu sach » su sach, te sach, tu cach
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
nam hoc » nam moc, nam hoi, am hoc
ma hanh » va hanh, da hanh, na hanh
cua tre » cua te, cuu tre, cua triet
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: ((((tu sach) or (thu sach))) or (thuat song)) ky tang xa hoi. hieu van nam hoc ma hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (thu sach))) OR (thuat song)) ky tang xa hoi. hieu van nam hoc ma hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (thu sach))) or (thuat song)) ky tang xa hoi. hieu van nam hoc ma hanh vi cua tre*.