Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
tu cach » tu cac
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
tang ha » lang ha, tang ma, trung ha
ky tang » ky nang, ky dang, kho tang
te sach » toc sach
ha hoi » hoa hoi, ha noi, xa hoi
ve cau » ke cau, va cau, ve cac
vi cua » di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (te sach)) ky tang ha hoi. hieu ve cau thuc va danh ((vi cua) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (te sach)) ky tang ha hoi. hieu ve cau thuc va danh ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (te sach)) ky tang ha hoi. hieu ve cau thuc va danh ((vi cua) OR (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (te sach)) ky tang ha hoi. hieu ve cau thuc va danh ((vi cua) OR (vai cua)) tre*.