Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau treo » cau theo, cau tren, cau triet
hoa hoi » khoa hoi, hoa hoc, hoa doi
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
thuc va » thuc vat, thuc dan, thuc day
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac
ha hoi » ha noi, xa hoi, va hoi
va nam » van nam, va nay
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: toc sach ky lang ((ha hoi) OR (hoa hoi)). hieu ((va nam) or (ha nam)) thuc va dan vai cau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang ((ha hoi) OR (hoa hoi)). hieu ((va nam) OR (ha nam)) thuc va dan vai cau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang ((ha hoi) OR (hoa hoi)). hieu ((va nam) or (ha nam)) thuc va dan vai cau treo".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang ((ha hoi) OR (hoa hoi)). hieu ((va nam) or (ha nam)) thuc va dan vai cau treo*.