| Number | Name | Date | Kind |
|---|---|---|---|
| 3892655 | Hickson | Jul 1975 | |
| 4060480 | Reed et al. | Nov 1977 | |
| 4176090 | Vaughan et al. | Nov 1979 | |
| 4216188 | Shabrai et al. | Aug 1980 | |
| 4238364 | Shabtai | Dec 1980 | |
| 4248739 | Vaughan et al. | Feb 1981 | |
| 4271043 | Vaughan et al. | Jun 1981 | |
| 4364848 | Castillo et al. | Dec 1982 | |
| 4377470 | Hettinger, Jr. et al. | Mar 1983 | |
| 4424116 | Hettinger, Jr. | Jan 1984 | |
| 4452910 | Hopkins et al. | Jun 1984 | |
| 4458023 | Welsh et al. | Jul 1984 | |
| 4637991 | Battiste et al. | Jan 1987 |
| Entry |
|---|
| "Soil Chemical Analysis-Advanced Course", 2nd edition, 11th printing, published by M. L. Jackson, 1979. |
| "Petroleum Refining", by James H. Gary and Glenn E. Handwerk, Marcel Dekker, Inc., 1975, pp. 86-95. |