Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
dang van » hoang van, hang va
truoc va » truc va, thuoc va, truong va
su sach » so sach, vu sach
tai cua » thai cua, tai cuc, tri cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
van lam » van nam
ky dang » ky nang, ky danh
va lam » va lap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (toc sach)) ky dang van hoa. lieu ((va lam) OR (van lam)) truoc va hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (toc sach)) ky dang van hoa. lieu ((va lam) OR (van lam)) truoc va hanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (toc sach)) ky dang van hoa. lieu ((va lam) OR (van lam)) truoc va hanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (toc sach)) ky dang van hoa. lieu ((va lam) OR (van lam)) truoc va hanh tai cua tre*.