Perhaps you should try some spelling variations:
cac thoi » cac toi, cac hop, cac tro
dong cac » duong cac, dong bac, dung cac
sac lanh » sac hanh, sac lenh, sach danh
lanh hai » manh hai, thanh hai, lang chai
cua viet » ca viet, hoa viet, cua vat
co sach » bo sach, cuon sach, hoc sach
hoc cac » hoc cao
ky dong » ly dong, ky dang, ky cong
hieu ve » hieu va, hieu van
dan sac » dac sac, ban sac, dan bac
hai cua » thai cua, dai cua, hoi cua
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((co sach) or (hoc cac)) ky dong cac thoi. hieu ve cac dan sac lanh hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((co sach) OR (hoc cac)) ky dong cac thoi. hieu ve cac dan sac lanh hai cua viet.
• Adding a wildcard symbol may retrieve word variants: ((co sach) or (hoc cac)) ky dong cac thoi. hieu ve cac dan sac lanh hai cua viet*.