SELECT CONTENTS FROM boxes EXCEPT SELECT T1.contents FROM boxes AS T1 JOIN warehouses AS T2 ON T1.warehouse  =  T2.code WHERE T2.location  =  'New York'
What types of contents cannot be found in warehouses in New York?
CREATE TABLE Warehouses (
   Code INTEGER NOT NULL,
   Location VARCHAR(255) NOT NULL ,
   Capacity INTEGER NOT NULL,
   PRIMARY KEY (Code)
 );
CREATE TABLE Boxes (
    Code CHAR(4) NOT NULL,
    Contents VARCHAR(255) NOT NULL ,
    Value REAL NOT NULL ,
    Warehouse INTEGER NOT NULL,
    PRIMARY KEY (Code),
    FOREIGN KEY (Warehouse) REFERENCES Warehouses(Code)
 );
INSERT INTO Warehouses(Code,Location,Capacity) VALUES(1,'Chicago',3);
INSERT INTO Warehouses(Code,Location,Capacity) VALUES(2,'Chicago',4) 
INSERT INTO Boxes(Code,Contents,Value,Warehouse) VALUES('0MN7','Rocks',180,3)