Perhaps you should try some spelling variations:
thuoc sach » nuoc sach, thuat sach, thuoc sinh
nang mai » nang ma, nang tai, lang mai
hoc sach » hoc sinh, hoc cac, hoc anh
mai hoi » mai khoi, dai hoi, lai hoi
va danh » va dinh, va dan, va hanh
doi dau » doan dau
cac luc » cau luc, coc luc, cac nuoc
luc va » duc va, tuc va, loc va
di dau » bi dau, di du, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thuoc sach) OR (hoc sach)) ky nang mai hoi. lieu va cac luc va danh ((di dau) or (doi dau)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thuoc sach) OR (hoc sach)) ky nang mai hoi. lieu va cac luc va danh ((di dau) OR (doi dau)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thuoc sach) OR (hoc sach)) ky nang mai hoi. lieu va cac luc va danh ((di dau) or (doi dau)) tren".
• Adding a wildcard symbol may retrieve word variants: ((thuoc sach) OR (hoc sach)) ky nang mai hoi. lieu va cac luc va danh ((di dau) or (doi dau)) tren*.