The phrase "completed in addition to" is correct and usable in written English.
It is typically used to indicate that something has been added to or done in addition to something else. For example, "The project was completed in addition to meeting the deadline."
NSF has extra forms that funding prospects may need to complete, in addition to Grants.gov's government-wide SF-424 (R&R) application.
(If the GP requests HADS or PHQ9 patients will be asked to complete them in addition to the BDI).
The Government Center, containing the new City Hall completed in 1968, in addition to federal, state, and private office buildings, thereby developed alongside Faneuil Hall and other adjacent historic buildings.
Although triptans are generally considered safe when used appropriately according to the approved label [37], physicians should obtain completed medical histories in addition to migraine symptoms and carefully evaluate the benefit risk trade-off before prescribing either triptans or NSAIDs.
One hundred forty, consecutive, adult patients referred to a pain management unit completed this inventory in addition to measures of pain, disability, depression, pain-related anxiety, and acceptance of pain.
The portion leading into Milford was completed by 1924, in addition to the segment of the road through Greenwood.
And now, 2,000 or so years after the Emperor Tiberius held his bacchanalia there at the Villa Jovis, local authorities in the exclusive Bay of Naples resort, where 1930s singing sensation Gracie Fields lived for more than 40 years, are guaranteeing visitors complete quiet in addition to the breathtaking panoramas.
In some cases, interns can receive housing as part of their complete package in addition to other benefits that would push the true value of their summer compensation even higher.
The HOOS includes the WOMAC in its complete form in addition to other questions about more strenuous activities.
