Sri Lanka standard code of practice for preparation of test samples, initial suspension and decimal dilutions for microbiological examination of food and animal feeding stuffs (SLS 393 part 1 : 2013 ; ISO 6887 - 1 : 1999 SLS 393 part 2 : 2013 ; ISO 6887 - 2 : 2003 SLS 393 part 3 : 2013 ; ISO 6887 - 3 : 2003 SLS 393 part 4 : 2013 ; ISO 6887 - 4 : 2003 SLS 393 part 5 : 2013 ; ISO 6887 - 5 : 2010 SLS 393 part 6 : 2013 ; ISO 6887 - 6 : 2013, 2013)