Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
ve cham » va cham, ve chat, vu cham
tai cuu » tai cuc, tai buu, tai cua
va hanh » van hanh, va thanh, va danh
cuu tre » cua tre, cau tren, cau treo
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
luc va » duc va, tuc va, loc va
ve cam » ve cac, va cam, ve cai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) ky dang xa hoi. hieu ((ve cam) OR (ve cham)) luc va hanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky dang xa hoi. hieu ((ve cam) OR (ve cham)) luc va hanh tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky dang xa hoi. hieu ((ve cam) OR (ve cham)) luc va hanh tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky dang xa hoi. hieu ((ve cam) OR (ve cham)) luc va hanh tai cuu tre*.