Standards and Industrial Research Institute of Malaysia & SIRIM. (1991). Specification for precast concrete pipes and fittings for drainage and sewerage part 2: Specification for inspection chambers and street gullies. Standards and Industrial Research Institute of Malaysia.

Standards and Industrial Research Institute of Malaysia and SIRIM. Specification for Precast Concrete Pipes and Fittings for Drainage and Sewerage Part 2: Specification for Inspection Chambers and Street Gullies. Shah Alam: Standards and Industrial Research Institute of Malaysia, 1991.

Standards and Industrial Research Institute of Malaysia and SIRIM. Specification for Precast Concrete Pipes and Fittings for Drainage and Sewerage Part 2: Specification for Inspection Chambers and Street Gullies. Standards and Industrial Research Institute of Malaysia, 1991.