Perhaps you should try some spelling variations:
thuoc ban » thuoc tan, thuoc dang, thu ban
cam thuoc » cay thuoc, nam thuoc, lam thuoc
vu khach » vu khanh, vu khac, vay khach
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu khach) or (thu sach)) ky tang xa hoi. lieu va cam thuoc ban hanh ((vai cua) OR (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu khach) OR (thu sach)) ky tang xa hoi. lieu va cam thuoc ban hanh ((vai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu khach) or (thu sach)) ky tang xa hoi. lieu va cam thuoc ban hanh ((vai cua) OR (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: ((vu khach) or (thu sach)) ky tang xa hoi. lieu va cam thuoc ban hanh ((vai cua) OR (hai cua)) tre*.