Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
tinh cua » trinh cua, sinh cua, tinh chat
va thanh » gia thanh, va tinh, le thanh
nam qua » nam quan, nam cua, nam mua
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
hieu ca » hieu cac, hieu cua, hieu va
sach ty » sach y, sach tu, sach thu
ca nam » cua nam, cai nam, ha nam
x hoi » xa hoi, o hoi, x ho

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