Perhaps you should try some spelling variations:
thanh thai » thanh hai, thanh tai, nhanh thai
nang tai » hang tai, tang tai, sang tai
thai cua » than cua, tai cuc, tri cua
va thanh » gia thanh, ban thanh, va tinh
cham duc » pham duc, cham soc, pham duy
nang cai » nang cao, nang cap, nang can
va cham » va chat, va tham
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet

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 ky) or (sach ty)) ((nang cai) OR (nang tai)) hoi. hieu va cham duc va thanh thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) ((nang cai) OR (nang tai)) hoi. hieu va cham duc va thanh thai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) or (sach ty)) ((nang cai) OR (nang tai)) hoi. hieu va cham duc va thanh thai cua tre".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) ((nang cai) OR (nang tai)) hoi. hieu va cham duc va thanh thai cua tre*.