Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham xuc » cam xuc, chat xuc, cham soc
cau tren » cu tren, dau tren, ca tren
doc hoc » duoc hoc, duc hoc, hoc hoc
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
xuc van » duc van, luc van, vuc van
hanh va » hang va, hanh vi
toc hoc » toan hoc, duoc hoc
sac ky » cac ky, sai ky
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sac ky)) nang ((doc hoc) or (toc hoc)). hieu ve cham xuc van hanh va cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang ((doc hoc) OR (toc hoc)). hieu ve cham xuc van hanh va cau tren.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sac ky)) nang ((doc hoc) or (toc hoc)). hieu ve cham xuc van hanh va cau tren*.