Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
sach ky » sac ky, sach y, sach ty
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
thuc va » thuc vat, thuc dan, thuc day
dau tai » dai tai, dat tai, da tai
buu tre » cuu tre
va nam » van nam, ha nam
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: doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) thuc va dau tai buu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) thuc va dau tai buu tre".
• Adding a wildcard symbol may retrieve word variants: doc sach ky lang xa hoi. hieu ((va nam) OR (va nay)) thuc va dau tai buu tre*.