| Business | Phone |
| Lindsay & Assoc Inc 323 W Galena Blvd, Aurora 60506 | (630) 264-1458 |
| Lorzx Consulting Corp 3106 Bennett Pl, Aurora 60502 | (630) 978-0665 |
| Unified Engineering 3056 Weber Dr, Aurora 60502 | (630) 851-4214 |
| Fuhrmann Engineering Inc Aurora 60504 | (630) 236-9770 |