Swanson, Bettye B., author
Macmillan, 1981
Buku Teks
Nickell, Paulena
John Wiley & Sons, 1959
Buku Teks
Nickell, Paulena
Wiley Eastern, 1970
Buku Teks
Gross, Irma H., author
Appleton-Countury Crofts, 1954
Buku Teks
Monaghan, Pat
Fairchild , 1948
Buku Teks