Perhaps you should try some spelling variations:
nay thuc » nam thuc, cay thuc, day thuc
hoa lang » hoa dan, hoa van
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
cao hoi » cau hoi, co hoi, cao hoc
va lang » va nang
hai cau » hai chau, hai chu, hai hau
y nang » ly nang, v nang, may nang
va nay » va ngay, va cay

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((y nang) or (ky nang)) cao hoi. lieu va nay thuc ((va lang) OR (hoa lang)) hai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ky nang)) cao hoi. lieu va nay thuc ((va lang) OR (hoa lang)) hai cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) or (ky nang)) cao hoi. lieu va nay thuc ((va lang) OR (hoa lang)) hai cau tren".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (ky nang)) cao hoi. lieu va nay thuc ((va lang) OR (hoa lang)) hai cau tren*.