Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cau phuc » cau truc, chau phu, huu phuc
phuc van » thuc van, phuc va, chuc van
van hanh » van thanh, ban hanh, van anh
hieu ve » hieu va, hieu van
y nang » ky nang, ly nang, v nang
ve cau » ke cau, va cau, ve cac
di cua » doi cua, de cua, do cua
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach y nang ((x hoi) or (x ho)). hieu ve cau phuc van hanh ((di cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach y nang ((x hoi) OR (x ho)). hieu ve cau phuc van hanh ((di cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach y nang ((x hoi) or (x ho)). hieu ve cau phuc van hanh ((di cua) or (dai cua)) tre*.