Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
ban hanh » ban hang
tuc ban » thuc ban, truc ban, tu ban
cam tuc » cam xuc, cam tu, nam thuc
hieu va » lieu va, hieu qua
su sach » vu sach
so sach » so sanh, bo sach, co sach
ca viet » va viet, co viet, hoa viet
v tang » 7 tang, 5 tang, 9 tang
va cam » va cham, va cac, va cao
vi ca » vit ca, li ca, va ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (so sach)) ((v tang) OR (6 tang)) mai khoi. hieu va cam tuc ban hanh vi ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) ((v tang) OR (6 tang)) mai khoi. hieu va cam tuc ban hanh vi ca viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) ((v tang) OR (6 tang)) mai khoi. hieu va cam tuc ban hanh vi ca viet*".