Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
vien cac » vien bach, vien dai, vien da
van hanh » van thanh, ban hanh, van anh
va tinh » may tinh
vai cua » dai cua, hai cua, lai cua
ve cac » va cac
y hang » ly hang, ty hang, yu hang
va hoc » van hoc
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: thu sach y hang va hoc. hieu ((ve cac) OR (vien cac)) nuoc ((van hanh) or (va tinh)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y hang va hoc. hieu ((ve cac) OR (vien cac)) nuoc ((van hanh) OR (va tinh)) vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y hang va hoc. hieu ((ve cac) OR (vien cac)) nuoc ((van hanh) or (va tinh)) vai cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach y hang va hoc. hieu ((ve cac) OR (vien cac)) nuoc ((van hanh) or (va tinh)) vai cua te*.