O`Brien duo in Yorkshire Oaks Aidan O`Brien is double-handed with Karsavina and Snowflake in the Stg#250,000 Aston Upthorpe Yorkshire Oaks at York on Wednesday.A field of nine was left in the contest after today`s final declaration stageMot Juste, runner-up to stablemate Lailani in the Kildangan Stud Irish Oaks last month, is among seven three-year-olds taking on two older horses in the Group One race.The older fillies are the four-year-old Sacred Song, smooth winner of the Halliwell Landau Lancashire Oaks at Haydock last month and Henry Cecil`s only runner at the York meeting, and Italian-trained five-year-old Super Tassa.Michael Bell has declared his Italian Oaks victor Zanzibar, who has not raced since being badly jarred up when finishing last in the Vodafone Oaks at Epsom in June.Yorkshire Oaks: Sacred Song, Super Tassa, Head In The Clouds, Karsavina, Mot Juste, Nafisah, Rockerlong, Snowflake, Zanzibar (9).