DEAR FRIEND,
first of all , i wanna thank all the honurable senior members who have shared alot of material on every subjects relating to all the competitive examinations in general and CSS in particular. As far as Sindhi is concerned in this regard, just one should solve last five years Questions Papers and make alot of real practice for securing good marks . Sir Akbar Legari's book is quite relevant to the Exam as a good number of CSPs suggested me the said writer's book. However, if one goes through last five years questions papers does come to know and decide to study SOP in a very short span of time. You may also contact me on this email(pervez_u2004@yahoo.com) for further guidance and consultations in the matter.
best of luck for CE-2013
regards,
PERVEZ ALI JAGIRANI BALOCH