Perhaps you should try some spelling variations:
sach doi » sach hoi, sach moi, sach dao
lang mai » lang dai, lang hai, lang man
cham hoc » cham soc, chat hoc, cham hoi
mai hoi » mai khoi, dai hoi, lai hoi
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach doi) or (sach y)) lang mai hoi. hieu vu cham hoc va danh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach doi) OR (sach y)) lang mai hoi. hieu vu cham hoc va danh vi cua te*.