Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
toc sach » hoc sach, doc sach, thuoc sach
nang mai » nang ma, nang tai, lang mai
thuc van » thuc vat, thuc dan, thuc va
van hang » van khang, van hoang, van thang
cua viet » ca viet, hoa viet, cua vat
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
ve tham » va tham, ve cham, vi tham
y nang » ky nang, ly nang, v nang
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang mai hoi. hieu ve tham thuc van hang va ((cua te) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang mai hoi. hieu ve tham thuc van hang va ((cua te) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: toc sach y nang mai hoi. hieu ve tham thuc van hang va ((cua te) or (cua viet))*.