Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
ban hanh » ban hang
lang hoa » hang hoa, lang ha, nang hoa
cac thuc » cach thuc, cac thu, can thuc
te sach » toc sach
van anh » van thanh, tuan anh, van minh
hieu va » lieu va, hieu qua
hoa hoi » khoa hoi, hoa hoc, hoa doi
ky lang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo
vi cuu » vi luu, vinh cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (doc sach)) ky lang hoa hoi. hieu va cac thuc ((ban hanh) or (van anh)) vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ky lang hoa hoi. hieu va cac thuc ((ban hanh) OR (van anh)) vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ky lang hoa hoi. hieu va cac thuc ((ban hanh) or (van anh)) vi cuu tre*.