LEARN THE MANY PERILS OF THE KASHRUT OF TEFILLIN AND MEZUZOT. JEWS UNWITTINGLY PAY FOR ARTICLES THAT ARE NOT KOSHER AND DON'T ACCOMPLISH THESE MITZVO, - By Rabbi Sholom Yehuda Gross, the head of the Rabbinical court of Holmin.

The Kashrut of Tefillin and Mezuzot

SAYINGS OF THE TALMUD MIDRASH AND ZOHAR CONCERNING THE IMPORTANCE OF THE OBSERVANCE OF THE MITZVAH OF TEFILLIN, - By Rabbi Sholom Yehuda Gross, the head of the Rabbinical court of Holmin.

The Importance of the Mitzvah of Tefillin

MOST OF THE MEZUZOT ARE NOT KOSHER

Article from Newspaper

A SOFER IS WILLING TO RETURN MONEY TO COSTUMERS BECAUSE HE HAD USED PARCHMENT WITHOUT HECHSHER

A Sofer acknowledges problem

STATISTICS ON THE KASHRUT OF MEZUZOT AND TEFILLIN

Vaad Mishmeret Stam

LAWS OF TEFILLIN AND MEZUZOT, - By Rabbi Sholom Yehuda Gross, the head of the Rabbinical court of Holmin. 

Mitzvah Encyclopedia Vol 4 - Tefillin and Mezuzot