Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
sach tinh » sach kinh, sac tinh, sach tranh
tinh hoc » sinh hoc, tin hoc, hinh hoc
thu hanh » thuc hanh, thu thanh, thuy hanh
trinh co » trinh do, trinh cong, trinh hoa
tu sach » thu sach, su sach, te sach
hoc ki » hoc ky, hoc kinh, hoc khoi

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 tinh hoc ki đong luc ) or ( thu hanh trinh co khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach tinh hoc ki đong luc ) OR ( thu hanh trinh co khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach tinh hoc ki đong luc ) or ( thu hanh trinh co khi đong luc ))*.