Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
nam thuc » nam thuoc, am thuc, nam thu
cau tren » cu tren, dau tren, ca tren
lang ha » long ha
lang xa » dang xay, lang van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
dan vai » dan va, dan vat, den vai
dan tai » van tai, dan thi, han tai
va nam » van nam, ha nam, va nay

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky ((lang xa) or (lang ha)) hoi. hieu va nam thuc va ((dan vai) or (dan tai)) cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky ((lang xa) OR (lang ha)) hoi. hieu va nam thuc va ((dan vai) OR (dan tai)) cau tren.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky ((lang xa) or (lang ha)) hoi. hieu va nam thuc va ((dan vai) or (dan tai)) cau tren*.