Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
cau tren » cu tren, dau tren, ca tren
hanh tai » thanh tai, hang tai, han tai
lang mai » lang dai, lang hai, lang man
mai khoi » mai khoa, tai khoa, cac khoi
cuu tre » cua tre, cau treo
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, su sach, tu cach
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
te sach » toc sach
ve tham » va tham, ve cham, vi tham

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) OR (te sach)) ky lang mai khoi. hieu ve tham thuc va hanh tai ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky lang mai khoi. hieu ve tham thuc va hanh tai ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky lang mai khoi. hieu ve tham thuc va hanh tai ((cuu tre) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky lang mai khoi. hieu ve tham thuc va hanh tai ((cuu tre) or (cau tren))*.