Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
cau tren » cu tren, ca tren, cau treo
ban banh » ban hanh, ban anh, ban danh
banh di » danh di, xanh di, banh chi
xuc ban » duc ban, cuc ban, quoc ban
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang o » nang co, nang ho, nang ro
va cam » va cham, va cac, va cao
o hai » co hai, so hai, o lai

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 o hai. hieu va cam xuc ban banh di ((cau tren) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang o hai. hieu va cam xuc ban banh di ((cau tren) OR (dau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang o hai. hieu va cam xuc ban banh di ((cau tren) or (dau tren))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang o hai. hieu va cam xuc ban banh di ((cau tren) or (dau tren))*.