Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
hanh tai » thanh tai, hang tai, han tai
su triet » su viet, su tien, ve triet
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
va hanh » van hanh, va thanh, va danh
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
ve cai » ve tai, ve cau
va cai » va cac, va bai, va dai
ve cac » va cac, vien cac
xuc va » duc va, tuc va, luc va
tai su » tai so, tai tu, lai su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ty nang ma hoi. hieu ((((ve cai) OR (va cai))) OR (ve cac)) xuc va hanh tai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ty nang ma hoi. hieu ((((ve cai) OR (va cai))) or (ve cac)) xuc va hanh tai su triet~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ty nang ma hoi. hieu ((((ve cai) OR (va cai))) or (ve cac)) xuc va hanh tai su triet*.