Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh dao » lanh dao, thanh dat, thanh dam
dan hanh » dang hanh, dan khanh, dan thanh
dang tay » dang xay, dung tay, dan tay
thuc dan » thuc hanh, hoc dan, thuc vat
dao cua » dai cua, day cua, dan cua
su sach » so sach, vu sach
tay hoi » tay ho, tao hoi, tay thai
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
va nam » ha nam, va nay

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky dang tay hoi. hieu ((va nam) OR (van nam)) thuc dan hanh dao cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (toc sach)) ky dang tay hoi. hieu ((va nam) OR (van nam)) thuc dan hanh dao cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ky dang tay hoi. hieu ((va nam) OR (van nam)) thuc dan hanh dao cua tre*.