Perhaps you should try some spelling variations:
van giao » nang giao, toan giao, dan gian
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach, vu sach
sach de » cach de, sach dao, sach dat
de xang » de dang, de tang, le xang
xang xa » lang xa, mang xa, ang xa
va giao » va giai, va gia, ve giao
va hanh » van hanh, va thanh, va danh
vai va » mai va, dai va, hai va
thiet » thieu

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 de xang xa hoi. hieu ((va giao) OR (van giao)) duc va hanh vai va thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach de xang xa hoi. hieu ((va giao) OR (van giao)) duc va hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach de xang xa hoi. hieu ((va giao) OR (van giao)) duc va hanh vai va thiet*.