Which preposition to use with whitlock

in Occurrences 2%

The Germans did not want Mr. Whitlock in Brussels, and nothing would have pleased them better than to have had him depart and leave them to their own devices, but, so long as he blandly ignored their hints that his room was preferable to his company and persisted in sitting tight, they submitted to his surveillance with the best grace possible and behaved themselves as punctiliously as a dog that has been permitted to come into a parlour.

to Occurrences 2%

Besides the copies of the letter I wrote to the Ambassador the only thing I got on my case was this letter, written by Mr. Whitlock to Baron von de Lancken, the official German representative in charge of the dealings with the American Embassy.

Which preposition to use with  whitlock