CREATE TABLE "workshop" (
"Workshop_ID" int,
"Date" text,
"Venue" text,
"Name" text,
PRIMARY KEY ("Workshop_ID")
)

CREATE TABLE "submission" (
"Submission_ID" int,
"Scores" real,
"Author" text,
"College" text,
PRIMARY KEY ("Submission_ID")
)

CREATE TABLE "Acceptance" (
"Submission_ID" int,
"Workshop_ID" int,
"Result" text,
PRIMARY KEY ("Submission_ID","Workshop_ID"),
FOREIGN KEY ("Submission_ID") REFERENCES `submission`("Submission_ID"),
FOREIGN KEY ("Workshop_ID") REFERENCES `workshop`("Workshop_ID")
)
SELECT Author FROM submission WHERE Submission_ID NOT IN (SELECT Submission_ID FROM acceptance)
Which authors did not submit to any workshop?