Perhaps you should try some spelling variations:
hanh sinh » hanh tinh, hanh dinh, hinh sinh
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
tan hanh » tan thanh, tang hanh, toan hanh
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
xay hoi » xa hoi, cay phoi, gay thoi
tay hoi » tay ho, tao hoi, tay thai
van hac » van hoc, van ha, van hai
hac duc » hoc duc, ha duc, thach duc
sinh cu » sinh cua, sinh cau, sinh cuc
cu tren » tu tren, dua tren

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky dang ((xay hoi) or (tay hoi)). hieu van hac duc tan hanh sinh cu tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang ((xay hoi) OR (tay hoi)). hieu van hac duc tan hanh sinh cu tren.
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang ((xay hoi) or (tay hoi)). hieu van hac duc tan hanh sinh cu tren*.