Perhaps you should try some spelling variations:
sach tay » xach tay, sach hay, sach tai
sach nay » sach hay, sach vay, sach nang
lang mai » lang dai, lang hai, lang man
cau tren » cu tren, dau tren, ca tren
mai hoi » mai khoi, dai hoi, lai hoi
qua cai » qua hai, qua cac, qua ca
cai duc » cao duc, mai duc, hoai duc
va dinh » van dinh, va kinh, va tinh
dinh di » dinh du, dinh vi, danh di
di cau » da cau, diem cau

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 tay) or (sach nay)) lang mai hoi. hieu qua cai duc va dinh di cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach tay) OR (sach nay)) lang mai hoi. hieu qua cai duc va dinh di cau tren.
• Adding a wildcard symbol may retrieve word variants: tu ((sach tay) or (sach nay)) lang mai hoi. hieu qua cai duc va dinh di cau tren*.