Perhaps you should try some spelling variations:
thanh tam » thanh tai, thanh tay, thanh nam
va thanh » gia thanh, ban thanh, va tinh
tay tang » tay lang, tay trung, tay quang
kham duc » pham duc, kham cuoc, pham duy
tu sach » thu sach, su sach, te sach
tam cua » nam cua, lam cua, dam cua
vu kham » vu khanh
hieu vu » hieu va, hieu ve, hieu su
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
ty tang » ty xang, ty hang, ky tang
ma hoi » xa hoi, ma hoa, me hoi

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 ((ty tang) OR (tay tang)) ((ma hoi) or (mai hoi)). hieu vu kham duc va thanh tam cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty tang) OR (tay tang)) ((ma hoi) OR (mai hoi)). hieu vu kham duc va thanh tam cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty tang) OR (tay tang)) ((ma hoi) or (mai hoi)). hieu vu kham duc va thanh tam cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty tang) OR (tay tang)) ((ma hoi) or (mai hoi)). hieu vu kham duc va thanh tam cua tre*.