Perhaps you should try some spelling variations:
hanh thai » nhanh thai, hinh thai, hanh tai
thai cua » than cua, tai cuc, tri cua
duc manh » suc manh, duc anh, duc minh
quoc ban » quoc bao, quoc lan, quoc quan
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach kem
nang ho » nang hoc, nang co, tang ho
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
ho hai » hoc hai, pho hai, cho hai

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 ky) OR (sach ty)) nang ho hai. hieu ve cac ((quoc ban) or (duc manh)) hanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang ho hai. hieu ve cac ((quoc ban) OR (duc manh)) hanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang ho hai. hieu ve cac ((quoc ban) or (duc manh)) hanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang ho hai. hieu ve cac ((quoc ban) or (duc manh)) hanh thai cua tre*.