Maya Widmaier-Picasso, the artist’s daughter, who autheticates his work, says that drawings sold on Costco are not by him. “Those two works, photographs of which were shown to her by The New York Times, were offered by the dealer with certificates in French saying that Ms. Widmaier-Picasso had authenticated them. Pointing to anomalies in the certificates — grammatical errors, wording that departed from her style, handwriting that did not match hers and the placement of words on the page — the artist’s daughter said both documents were forgeries.”