[aron]

Here is an extract from a N. Tomes article on WL appropriating material without attribution.

"W. Lee declared, 'In my speaking I have rarely referred you to some other writings. I did this purposely. Books such as Andrew Murray’s The Spirit of Christ, however, I did have and still have the peace to refer you to.' [W. Lee, “Concerning the use of Reference Books and other Writings” in Elders’ Training Book 4, p. 14] Generally only LSM publications were endorsed."

"The flagship NT Recovery Version reflects this reluctance. References to others are scarce. W. Lee refers to Andrew Murray’s book, “The Holy of Holies” in Elders’ Training Book 4, p. 132. Occasionally W. Lee referred to other writings—James McKendrick’s Seen and Heard, William Law’s Power of the Spirit, Brother Lawrence’s Practicing the Presence of God, Darby’s Synopsis of the Books of the Bible, Mary McDonough’s God’s Plan of Redemption and Pember’s Earth’s Earliest Ages. Govett and Panton were also cited on occasion. The general impression, however, was that these authors’ insights have already been incorporated."

I think the intended effect of failing to cite others is to get the reader to look away from them, and focus solely on the author.

Being sloppy, vague, or absent citations may be okay in writing a personal communication, or even an internet forum post. But it is less so, by a considerable margin, if one is presenting a "professional" document. I remember when someone showed me a RcV NT, held up the pages to the light showing how thin they were, and showed me that it was printed by University Printers in Cambridge England. Clearly a high standard was being implied there.