Perhaps you should try some spelling variations:
canh tac » canh tay, canh giac, cong tac
van hanh » van thanh, ban hanh, van anh
dat tren » dat trong
dua tren » dung tren
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky canh » ky anh, ky cach, ky danh
tac hoi » tao hoi, tay hoi, tac hai
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
va cam » va cham, va cac, va cao

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 ky canh tac hoi. lieu va cam luc van hanh vi ((dat tren) OR (dua tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky canh tac hoi. lieu va cam luc van hanh vi ((dat tren) OR (dua tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky canh tac hoi. lieu va cam luc van hanh vi ((dat tren) OR (dua tren))*.