Perhaps you should try some spelling variations:
toc sach » thuoc sach, nuoc sach, toc san
hoc sach » hoc sinh, hoc cac, hoc anh
nay thuc » nam thuc, cay thuc, day thuc
doc sach » nuoc sach, dac sac, bo sach
ky dinh » ky sinh, ky danh, ky kinh
dinh xa » dinh ba, dinh va, dinh xu
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
dau vai » dau va, dau hai, dau tai
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
va nay » va ngay, va cay
va dau » va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((((toc sach) or (doc sach))) or (hoc sach)) ky dinh xa hoi. hieu va nay thuc va dau vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((toc sach) OR (doc sach))) OR (hoc sach)) ky dinh xa hoi. hieu va nay thuc va dau vai cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((((toc sach) or (doc sach))) or (hoc sach)) ky dinh xa hoi. hieu va nay thuc va dau vai cuu tre*.