Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, te sach, tu cach
hoc doi » hoc dai, hoc noi, hoc moi
hanh le » thanh le, hanh ve, hanh de
thu van » thuc van, thuy van, tu van
hiem he » hiem xe, hieu he, thien he
cua tre » cua te, cuu tre, cua triet
hoa doi » hoa dai, xoa doi, hoa duoc
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
he nam » ha nam, nghe nam
le cua » ly cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (su sach)) ky lang ((hoa doi) OR (hoc doi)). hiem he nam thu van hanh le cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky lang ((hoa doi) OR (hoc doi)). hiem he nam thu van hanh le cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky lang ((hoa doi) OR (hoc doi)). hiem he nam thu van hanh le cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky lang ((hoa doi) OR (hoc doi)). hiem he nam thu van hanh le cua tre*.