Perhaps you should try some spelling variations:
thuoc sach » nuoc sach, thuat sach, thuoc sinh
nay thuc » nam thuc, cay thuc, nhan thuc
hoc sach » hoc sinh, hoc cac, hoc anh
day thuc » dan thuc, cay thuc, dai thuc
vai cuu » vai cua
dan vai » dan va, dan tai, dan vat
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
va dan » ca dan, va dao, va dau

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 xa hoi. hieu va ((nay thuc) OR (day thuc)) va dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (hoc sach)) ky lang xa hoi. hieu va ((nay thuc) OR (day thuc)) va dan vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) or (hoc sach)) ky lang xa hoi. hieu va ((nay thuc) OR (day thuc)) va dan vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) or (hoc sach)) ky lang xa hoi. hieu va ((nay thuc) OR (day thuc)) va dan vai cuu tre*.