Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hanh de » hanh ve, hanh kem
xuc van » duc van, luc van, vuc van
cua cay » cua cac
cao hoc » co hoc, cho hoc, chat hoc
ty nang » ky nang, ty xang, ty hang
de cua » le cua, te cua, dieu cua
ve cac » va cac

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