Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
cac truc » cau truc, cac tru, cac trung
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
can cau » van cau, ban cau, cac cau
tu sach » thu sach, su sach, te sach
_ lang » o lang, _ land
y lang » o lang, tay lang, yen lang
ca cau » cua cau, cac cau, ca cac

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 ((y lang) OR (_ lang)) mai khoi. hieu va cac truc va danh ((ca cau) or (can cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y lang) OR (_ lang)) mai khoi. hieu va cac truc va danh ((ca cau) OR (can cau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y lang) OR (_ lang)) mai khoi. hieu va cac truc va danh ((ca cau) or (can cau)) treo".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y lang) OR (_ lang)) mai khoi. hieu va cac truc va danh ((ca cau) or (can cau)) treo*.