As interest rates rise, it gets tougher to collect receivables from cash-strapped customers. So here are two timely guides:

· The Complete Book of Collection Letters, Telephone Scripts, and Faxes (McGraw-Hill, 1994, $69.95), by Cecil J. Bond, a credit consultant, comes with an IBM-compatible disk that allows readers to tailor its 400-plus documents for their own collection problems. It's pricey but useful, especially for companies without a full-time accounts-receivable clerk.

· Collection Techniques for a Small Business (Oasis Press, 800-228-2275, 1994, $19.95), by Gini Graham Scott and John J. Harrison, offers suggestions to upgrade your accounts receivable. For example, the authors advise adding collection-cost clauses to contracts, and they offer tips for motivating prompt payment.

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