Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang mai » nang ma, nang tai, lang mai
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu ke » hieu kem, chieu ke, hieu ky
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ke cau » ket cau
luc 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: ((su sach) or (thu sach)) y nang mai hoi. hieu ke cau ((luc va) or (duc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu sach)) y nang mai hoi. hieu ke cau ((luc va) OR (duc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu sach)) y nang mai hoi. hieu ke cau ((luc va) or (duc va)) hanh vi cua tre*.