Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang hoc » nang doc, nang luc, dong hoc
vuc van » duc van, luc van, thuc van
cua cau » cua chu, cua can, cua cu
van anh » van thanh, tuan anh, van minh
cac vuc » cac nuoc, cac vung, cac cuoc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
hoc hoc » hoc hoa, toc hoc, hoc hoi
ty nang » ky nang, ty xang, ty hang
ve cac » va cac, vien cac
anh vi » hanh vi, anh va, anh ve

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