Perhaps you should try some spelling variations:
thuc dan » thuc hanh, hoc dan, thuc vat
bo sach » co sach, hoc sach
sach ky » sac ky, sach y, sach ty
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
hieu he » hieu ve, hiem he, hieu le
thuc va » thuc vat, thuc day
he nam » ha nam, nghe nam
dan vi » doan vi, don vi, dan va
vi hoa » voi hoa, vi hoc, va hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ky mang may hoi. hieu he nam ((thuc va) OR (thuc dan)) dan vi hoa viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ky mang may hoi. hieu he nam ((thuc va) OR (thuc dan)) dan vi hoa viet".
• Adding a wildcard symbol may retrieve word variants: bo sach ky mang may hoi. hieu he nam ((thuc va) OR (thuc dan)) dan vi hoa viet*.