Perhaps you should try some spelling variations:
nguoi sach » nguoi san, nuoc sach
tham thuc » nham thuc, pham thuc, tam thuc
cua triet » cua viet, su triet, va triet
qua tham » qua cham, qua than, qua thanh
te sach » toc sach
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
thuc va » thuc vat, thuc dan, thuc day
ha hoi » hoa hoi, ha noi, xa hoi
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (nguoi sach)) ky lang ha hoi. hieu qua tham thuc va dan di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (nguoi sach)) ky lang ha hoi. hieu qua tham thuc va dan di cua triet.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (nguoi sach)) ky lang ha hoi. hieu qua tham thuc va dan di cua triet*.