Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
chat hoc » chat hoa, chat thom, cho hoc
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
sach ty » sach y, sach tu, sach thu
cua cau » cua cac, cua chu, cua cay
hieu ve » hieu va, hieu van
cao hoc » co hoc, cho hoc
ty nang » ky nang, ty xang, ty hang
anh vu » hanh vu, anh tu, anh va
anh ve » hanh ve, anh va, anh viet
ve cac » va cac, vien cac

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 ty nang ((cao hoc) OR (chat hoc)). hieu ve cac vuc van ((anh vu) or (anh ve)) cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang ((cao hoc) OR (chat hoc)). hieu ve cac vuc van ((anh vu) OR (anh ve)) cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang ((cao hoc) OR (chat hoc)). hieu ve cac vuc van ((anh vu) or (anh ve)) cua cau*".