Perhaps you should try some spelling variations:
mang mai » mang may, lang mai, mang lai
hanh dan » thanh dan, canh dan, hanh dao
hanh san » thanh san, khach san, thanh son
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky mang » ky nang, ke mang, ky dang
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
su viet » so viet
tuc va » thuc va, truc va, tuc xa

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 mang mai hoi. hieu va cac tuc va ((hanh dan) OR (hanh san)) su viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky mang mai hoi. hieu va cac tuc va ((hanh dan) OR (hanh san)) su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky mang mai hoi. hieu va cac tuc va ((hanh dan) OR (hanh san)) su viet*.