Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thu sach » tu sach, thuat sach, thu hoach
nam thuc » nam thuoc, am thuc, nam tu
cau tren » cu tren, dau tren, ca tren
lang xa » lang ha, dang xay, lang van
va tinh » may tinh
tinh di » tinh doi, trinh di, tinh da
hieu ve » hieu va, hieu van
o lang » hoa lang, hoi lang
di cau » da cau, diem cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) or (thuoc sach)) o lang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va tinh di cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) o lang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va tinh di cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuoc sach)) o lang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va tinh di cau tren".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuoc sach)) o lang xa hoi. hieu ve ((nam thuc) OR (nam thu)) va tinh di cau tren*.