Perhaps you should try some spelling variations:
thuoc sach » nuoc sach, thuat sach, thuoc sinh
nay thuc » nam thuc, cay thuc, day thuc
hoc sach » hoc sinh, hoc cac, hoc anh
lang van » dang van, tang van, hoang van
dan vat » dang vat, van vat, dan va
dan vai » dan va, dan tai, den vai
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
van hoi » van hoa, van hoc, van hoe
ky lang » ky nang, ky dang, ky tang
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: ((thuoc sach) or (hoc sach)) ky lang van hoi. hieu va nay thuc va ((dan vai) OR (dan vat)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (hoc sach)) ky lang van hoi. hieu va nay thuc va ((dan vai) OR (dan vat)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (hoc sach)) ky lang van hoi. hieu va nay thuc va ((dan vai) OR (dan vat)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (hoc sach)) ky lang van hoi. hieu va nay thuc va ((dan vai) OR (dan vat)) cuu tre*.