Perhaps you should try some spelling variations:
ngang hoa » nganh hoa, nang hoa, nganh khoa
doc sach » hoc sach, nuoc sach, dac sac
toc sach » hoc sach, thuoc sach, nuoc sach
ty ngang » ly ngan, te ngan, tu ngan
cac luc » coc luc, cac nuoc, cac cuoc
cau luc » cau truc, cau phuc
cua cau » cua cac, cua chu, cua cay
hieu ve » hieu va, hieu van
anh vi » hanh vi, anh va, anh ve
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) OR (toc sach)) ty ngang hoa hoc. hieu ve ((cac luc) or (cau luc)) tuan anh vi cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (toc sach)) ty ngang hoa hoc. hieu ve ((cac luc) OR (cau luc)) tuan anh vi cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (toc sach)) ty ngang hoa hoc. hieu ve ((cac luc) or (cau luc)) tuan anh vi cua cau*".